Her money, her purchases, her name. She can will her estate to her husband, if she likes. Or better still, share it between him and her children.
Legally, you are not one. Spell out both your names on all joint documents.
Spiritually sef, you are not one. On judgement day (whichever version you believe), each of you will answer your case separately. See?
Use both your names. Feel free to use your own name too where you prefer.