I'd just do whatever is working. If she's happy with no day feeds, then I guess just leave it.
DS has just started dropping feeds & cutting right back. I just give it when he wants it.
Usually just his day sleep & once over night, then if upset or bored wanting a quick drink through the day.
I don't think she needs a certain amount. Whatever she is happy with. DS has never settled through the night with out it, but would your DH try to settle her for a feed & see if she'd drop one over night?