Decided on Keziah nn Kezzie or Kizzy (not sure which would work best) for the sister.
Got three I'm undecided on for the daughter.
Jasmine/Jazmine/Jazmyn - It's got a pretty, feminine sound. With Z's in Thirza and Keziah it's plausible the trend could be carried onto the next generation, so I'm undecided on the spelling. I know I said no trendy spellings, but the more I think about it, the more I think Jazmyn would be more suited to the little girl than Jasmine.
Isabella/Izabella - Ditto the above. Yes it's very popular, frilly and appealing to young mums, and I like the fact she could be an Izzy or a Bella depending on her personality. I wouldn't use the nickname much, she'd be referred to as the full name in the narrative, but is Izzy and Kezzie/Kizzy going to be too much, or would it be a nice quirk to nickname her close to her aunt?
Liberty - I like the meaning of 'freedom' - appropriate for the daughter of someone who ran away at 16 or just plain cheesy? Would use occasional nn Libby.