If you and your boyfriend owned the dog jointly, your boyfriend’s daughter may only be entitled to one-half its value. If you want to keep the dog, you may have to buy out her interest in the dog. If the dog belonged to your boyfriend, his next of kin will be legally entitled to all of his assets, even the dog. If you live in a state that recognizes common-law marriage and you meet the requirements for a common-law marriage, you may be entitled to a share of your boyfriend’s/husband’s estate, including the dog.