My understanding is that if the current owner is in one state and the new owner is in another state, federal law states handguns have to go through a FFL.
TRANSFERS OF FIREARMS BY
PRIVATE SELLERS
An unlicensed individual may transfer a firearm to another unlicensed individual residing in the same State, provided that he or she has no reason to believe the buyer is prohibited by law from possessing firearms.
For a list of categories prohibiting a person
from possessing a firearm, please refer to 18
U.S.C. 922(g) and (n).
An unlicensed individual is prohibited from directly transferring a firearm to a person residing in another State.
Regardless of the purpose of the transfer (e.g. gift, trade, loan, sale, ownership, etc.), this restriction applies to all types of firearms. An unlicensed individual may complete a transfer to an out-of-State person through the following procedure:
• The unlicensed individual transfers
the firearm to a Federal Firearms
Licensee (FFL) located in the State of
the person receiving the firearm.
• The FFL will transfer the firearm to
the unlicensed out-of-State person.
• The FFL will be responsible for
lawfully transferring the firearm.
ATF SourceWith our UBC, I am not sure if a FFL will transfer a handgun to a 18 year old. There has been debate here in the state between gun rights groups and the state govt. and I do not know the current status of that debate. You may want to research this or maybe someone with more info then I have will chime in and clarify. I would not want you to send it to a FFL here and not have her be able to get it from the FFL.