I hadn't realised that ther was a family connection- Anielka may have told me at some time, but I find it very hard to get my brain to sort all these family relationships out.
I can see why she would appeal to Jane, if she was bookish. I can understand, too, that she wouldn't want to go public on her relationship with Jane later in life, when the Knights and the Austens were so carefullly re-creating her image, either.
I just have the impression of her as having a great sense of humour- though for the life of me I cannot tell you why. And what stories she could have told about the Austens, if she had been inclined!