Make sure its not her clothes she is growing out of! My little boy always starts to leak if his vests/sleepsuits are too small, I assume as the nappy expands in the night it becomes a barrier and leaks, I always size up in those quicker than I need to for his daytime clothes.
We always size up once he starts leaking at night ☺️
We use lidles own nappies and never had an issue. Our girl is 4 months and sleeps through the night
Mammia from Aldi are pretty good, second best to pampers new baby but a lot cheaper x
Size up