If you have an adapter plug pigtail that will convert the 30amp 120 Vac power port plug on the side or back of the trailer to a 15 amp 120Vac plug, then you just run a #12 wire extension cord into the house and plug her in. The battery will charge. Here are links to example pigtails:
I acquired all my electrical power cords from this outfit.
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic model 30 twin beds, 50 amp service, 900 watt solar system, Centramatics, Dill TPMS, disc brakes, 16" tires & wheels