Is she around 4 months old? If so, this sounds like the 4 month wakeful. It's basically the devil coming out in your child. I'm kidding! Kind of...
It's a short phase, it passes in a couple of weeks or so. It's not necessary to sleep train. I remember ds got up 15 times one night!
This. DS started his four month wakeful around 3.5 months. He went from sleeping 8pm-6am to waking up 4-5 times a night, then around 8 times, and just now he's down to just once a night at 4.5 months old. Your LO is definitely too young to sleep train at 3 months old. Recommended age is 6 months. If your baby is crying, it's because she needs you, so grab a coffee, a magazine, and rock your baby.