What if my daughter has my last name and her father never sees her and I am getting married and she would like to cahnge her name too?

How old is the child? It depends on where you live but GENERALLY she needs her father's consent.

What if my daughter has my last name and her father never sees her and I am getting married and she would like to cahnge her name too?

Your fiancé might want to also consider adopting her. In some places, but not all, you would have to be married for at least a year. That would have the effect, among other things, of changing your daughter's last name. The adoption option also requires notice to and consent by the biological father. Sometimes there are grounds for dispensing with the consent requirement.

Under 18 you will need the bio father to sign for any name change or adoption,

After 18 the child can change their name to anything they want