The theory I then proposed (which was actually the brainchild initially of the now-unknown "Bob" on the VN board) was that Elizabeth's and Roger's father, Jamison (who would have been in his 60s I think -- I worked all this out), fathered VW with young Betty Hanscomb, the daughter of Collinwood servant "B. Handscomb." Therefore VW was Elizabeth's half-sister.
That's where you came in, Cassandra B., taking all this a step further and making an even more compelling case for Betty Hanscomb (not Victoria) being Elizabeth's half-sister. In other words, Jamison's infidelity had occurred when he was a much younger man, and he fathered Betty Hanscomb. This scenario explains why the sketch of Betty Hanscombe resembles both Elizabeth and Victoria Winters (Betty's daughter).
But I'm forgetting the important detail of whom the father was -- could it have been Paul Stoddard? Yes! I think that was it -- and that was your brilliant contribution :D , CassB: Betty was Elizabeth's half-sister (the illegitimate daughter of Jamison Collins); and then Elizabeth's new husband, Paul, carried on an affair with Betty, producing Victoria. This accounts for all of the facts, including the difficulty of explaining how Elizabeth supposedly bore a child without anyone every whispering about it, her brother Roger knowing about it, etc.
This also accounts for the relatively large age diffference between Elizabeth and Roger--- eight years according to their family bible (18 years according to "Shadows on the Wall"):
Ennui sets in between Jamison and his wife.
Jamison engages in affair with the sister of the butler Hanscombe, who was, most likely, working as a maid.
She gets pregnant, and perhaps, dies in childbirth. If so, the butler, at first not aware of the ID of the baby girl's father, names her Elizabeth, either as a compliment to his boss's legitimate daughter, or after one of his own relatives. If however, the young mother survived, maybe she chose the name to express her resentment that Jamison would not leave his family for her. In any case, the two little girls are nicknamed Liz and Betty, so they don't get called to the wrong supper tables.
Jamison's wife discovers the affair, and the birth. Jamison refuses to send away his inconvenient second family. Ennui turns to estrangement for a couple of years.
Then something happens--- either the butler's sister has left, due to marriage or a better job opportunity, or, more likely, has died, which would better explain why Betty was raised by her uncle. Plus, the death of her rival would be more likely to soften the attitude of Jamison's wife.
She consents to let the two half-sisters become playmates, though always reminding them of the difference in status. She also reconciles with Jamison, and nine months later, little Roger is born. It is not stated in the program at which point Liz and Roger's mother has died, though SotW has the now-middle-aged "Carolyn" (for whom Liz later names her own daughter) dying in childbirth.
If so, at that point, Jamison really begins to indulge ALL his children, including Betty, having her portrait painted by Sam Evans (but, due to his death soon afterward, never delivered), and sending her to school in NYC. There, unfortunately, she meets Paul Stoddard and his disreputable friend Jason McGuire. Despite the example of her own late mother, Betty falls in love with Paul, and is soon made pregnant.
She finds out that her father has just died, but her funds have been cut off. This, then,
could be evidence that Jamison's spiteful wife was still alive, or that Liz realized the "truth" about her father and was P.O.'d at the moment, or, perhaps, Jamison's sister Nora (like Justin's sister Julia in PT 1841) had something to do with it. Anyway, Paul soon tires of his now-penniless, pregnant girlfriend, who has, moreover, told him all about her wealthy half-sister back in Maine. He leaves her, with a lie that he will personally appeal to Liz to give Betty her rightful share of the inheritance. Jason stays in NYC, "befriending" Betty, for the time being.
Of course, you know the rest--- Paul wasted no time in courting and wedding the frustrated Liz, who has had to manage her father's business, oversee Roger's care, and perhaps deal with her difficult mother, thus leaving little time for romance, and her biological clock ticking away. Liz got pregnant a year later, and Paul, with Jason's connivance, managed to keep Betty from contacting her. Liz's mother must have died by that time, and the new baby was named for her.
Meanwhile, Betty bore her own child in NYC, shortly found she couldn't support her, and, "helped" by Jason, dropped her off at the orphanage. Either one of them could have written the note, so the handwriting didn't match Liz's. Miraculously, the baby Victoria was not adopted in the interim. Finally, Jason left Betty and went to join Paul, who about to abscond with some Collins funds, and wanted his share. He may have brought a letter from Betty, which Liz would have found in Paul's luggage after she thought she killed him.
By this time, Vicki was a toddler, and Liz was alone with her own baby Carolyn, having sacked everyone except Mathew Morgan, and Hanscombe, whom she probably paid off, along with his niece--- her half-sister--- so they would both disappear. Sick of the consequences of their involvment with the Collinses and their in-laws, they might have gone willingly--- Betty, now relieved of responsibility for the daughter she hadn't held since Vicki was an infant, anyway.
Out of guilt, Liz then paid for Vicki's care and education, which also kept her from being adopted, though one could understand why she wouldn't have been willing to RAISE the child. She also kept track of Vicki's life in the orphanage; she told Roger that the girl had a lonely childhood there. Sympathy, curiosity, and a desire to do finally do right by her niece/stepdaughter, who apparently had not inherited any bad qualities from her erring parents, caused Liz to bring Vicki "home"--- but in a subordinate position.
Little is explained by Liz's reaction when Roger, at first, sexually harrassed Vicki. After all, her own daughter, Carolyn, was, more or less, flirting with her uncle. (rather suggestive for 1966!) Still, Roger wasn't trying to break into HER bedroom, as far as we know. Liz displayed anger when her brother bothered Vicki, but not the outrage one would have expected if he had actually made an advance on a child of hers.
All that much having been said, IF they had brought back the Vicki character, even without Alexandra Moltke (Betsy Durkin--- No! Carolyn Groves--- Si!) and Liz, was, after all, revealed to be her mother, given that an ordinary mortal Dad wouldn't have been exciting enough by then, I nominate Nicholas Blair. (Well, he had all those powers--- he COULD have made himself look like someone else back in 1945, or maybe, he and Liz were made to FORGET their affair, by Diablos.)
Adding a little confusion to your day.
L.