does the biological father have to sign as well for our daughters last name to be changed, or is that something i (the mother) can do myself?

Question

does the biological father have to sign as well for our daughters last name to be changed, or is that something i (the mother) can do myself?

Answer

Having him sign off on it makes it easier, but is not necessary. You can petition the court, send him notice, and if he doesn't respond, the court should still grant the name change.