S.
I wouldn't worry too much about it at this point. Either put pull-ups on her at night, or be prepared to change and wash sheets everyday. I had 2 bedwetters and neither had problems with the pull ups leaking. I usually bought the cheapest store brand that I could find. But it sounds like maybe she's peeing several times a night instead of just once. And it sounds like overworked kidneys, instead of her being a heavy sleeper.
Talk to your pediatriain. Our bodies produce a hormone called DDATP (I think, it's been a few years) that causes our kidneys to slow down at night, therefore the bladder isn't constantly full. My kids were older before their doctor was ready to try this though. Once they were started on the DDATP, the bed-wetting stopped almost immediatly and the only accidents were when they forgot to take their medicine (1 tablet at bedtime). Since the DDATP is naturally occuring, there are no side effects, and your body eventually figures out that it needs to start producing more of this hormone in the evenings, so this is NOT a permanent thing. I think one child was on for about 6 months and it took the other about 18 months.
Sleep apnea can also be a cause, along with enlarged tonsils - which can cause sleep apnea. The child sleeps so fitfully just trying to breathe, that when they finally relax into a deep sleep, they are dead to the world so to speak, and are just too tired to wake up. (again, 1 child had large tonsils and sleep apnea which were both taken care of by removing the tonsils; the other child rarely had a cold).
Again, the bedwetting at her age doesn't concern me as much as the fact that she is perhaps wetting 2-3 times per night. Neither one of you is getting any sleep.