I like the idea of Talia (tal-ya) or Tallulah being Tilly for short. I could also see Tilda or Clotilda.
Secretly I like Tillandsia but I'm not really going to use it and probably nobody else is either.
Talise or Talitha maybe?
Or just name her Tilly.
My first thought, besides Matlida, was Ottilie. It's unusual but still pretty. There's also Ottoline.
Ottilie was the first one that came to mind. Or maybe Ottaline? Also possible: Natalie, Catalina,