Should i get a job even though it would be hard?

Your dad wants you to spend some time with you in the summer I do not think not going would be considered an inconvenience. A disappointment would be a better word. I suggest you call your dad and tell him what mom wants you to do. I suspect if it is money he would be glad to give you 20 or 40 dollars for your hamster rather than loose that little time he has with you. I really question you moms motive. Call you dad, he can give you better advise than we can!!