Can my boyfriends Sister sponsor our family?

[Leah Cawkwell]

My boyfriends sister is a us citizen and will sponsor him(a uk citizen) however we have a son and wish to marry will this effect the sponsorship, can she sponsor us all? Or if we do not marry before his sister sponsors him how will this affect our family? Can He then sponsor us when He gets a green card?

[inadmissible]

You do know the wait time for a sibling green card is like 14 years, right?