Are these things normal?

My mom's got me all worried saying there's something wrong with my daughter :( are these things normal of most kids her age(15 months)?

-shes never been a good sleeper and cries herself to sleep every night and naptime (I do a comforting routine and shes fine until I put her in the crib, the sce screams for 10-20 minutes every time)

- shes throwing tantrums all the time and lately just so miserable

-she throws all of her food on the floor at every meal time

Personally I have never worried about these things, but I think my mom's really been getting in my head lately :(

This all came up because she isn't able to sleep at daycare and I dont know how to fix that problem. The daycare says she can't be awake at naptime because that's their break time, but she just can't sleep in a room full of kids! So much stress!