How many wet nappies should there be in an almost 2 year old in 24 hours?

DD3 has had gastro for over 36 hours now. Still breast feeding, but only keeping very minimal amounts down. Also has extremely liquified diarrhea & an on/off fever.
I'm thinking it was a pretty dry nappy this morning, but it was filled before I could really tell. No wee's since then - about 7.30am (nearly 10 here now).
Lips slightly drier than usual, but not cracked. Still bright, alert & cheeky

I've never had a gastro bug last longer than 24 hours (except DD2's rota virus), so I'm not sure if I should be worried or not. I planned on seeing how she went over night, & over night she was dry wretching, but she started keeping small feeds down (after she brought the bigger ones up) .

So after not chucking since about 5 this morning, I was going to wait & see, & if she went again, take her to the gp. She just vommited again, but she's still so bright & alert that I'm not sure she's that bad.

Should have her checked over?