S.H.
Night-time dryness... is not something attained until even 7 years old, and this is normal. And per Pediatricians. It has to do with biological development... and is entirely different than day-time toileting.
Your girl is normal.
My daughter, was already 5 years old, when she went from night diapers, to underwear at night for sleeping.
Normal.
My son, is 3 and uses diapers at night too... because he is still wet during the night and for naps. Normal.
Pull-ups, are useless, at night, because it does NOT hold much and it is expensive.
Huggies night diapers are better.
ALSO, get some waterproof bed-pads... to put directly under her at night. That way, it is easier clean up and you won't have to wash all your bedding. I have 4 of them, which I use with my kids... and just rotate them. I got mine from Amazon.
Potty training for daytime... for your girl, is not completed yet. She is not yet ready or able. Common. My son, again, is 3 and he is still learning.... so that's fine. I don't pressure him.
Do NOT expect daytime dryness and night-time dryness to happen at the same time. It does NOT. These are 2 different things. And has to do with the maturity of their biological development/nerve development/bladder and brain connections, too.
Just keep trying... and she will get it. But don't scold for it... or the child will not want to.
all the best,
Susan