You have those things and that is about loving and caring for yourself. That is what people do for themselves so they don't have to rely on others for all of their needs. If you can't afford them, however, you are not loving yourself properly either. Doing things for yourself that cause you to negate or sacrifice other things, like bills, etc. is not healthy. If you can't afford the dolls, be happy with the ones you have and enjoy them.

If you live with your mother, you must respect her wishes about the hamsters. She apparently allowed you to have the ones you have or had, so it is not unreasonable for her to refuse to allow any more.

If you are obsessed with these things at the expense of other people or having other outside interests, that is not healthy either and your mother is doing what she should do, guide her daughter to a healthier emotional state and sense of well being.