Am I able to be claimed as a dependent?

Some info about my situation:
I turned 24 in 2018. I graduated from school in May 2018 and got married the same month. While in school I lived in a dorm and paid my own expenses with a part time job, and since graduating my husband and I have lived at my mother’s house. She paid all house expenses except for gas and electric which we split with my brother. The rest of our expenses we paid ourselves. I worked on and off for the rest of the year and in total made about $5300.

Now my question: can my mother claim me as a dependent? We would like to file jointly in order to get the benefits of being newly married but she claims that she can claim me since I was in school 5 months of the year. She also says that not claiming me would mean having to pay a lot back to the IRS since she said she would claim me on her w4 at the beginning of the year.

Is she allowed to claim me?