Is this embezzlement?

when my dad had passed away he had me on his life insurance policy along with my mom, my brother and my sister. that insurance check came in july and my mom had given my siblings there amount of the check excluding me out. it is now february and my mom just now gave me a check. the problem is, my check was only for 5,000 when it was suppose to be 10,000 to 20,000. (i dont know the exact amount but in that range) she said she has been paying for things out of my money with out my permission or my knowledge of even knowing she was doing that. is this in fact embezzlement? and what could i do to get my full amount?