to the Future 3.
The girl in the past (Clara Clayton) is actually the love interest of the father figure (Doctor "Doc" Emmet Brown). The one the young man (Marty mc Fly) sees in the present is his own love interest, Jennifer.
From Wikipedia:

Clara applies the emergency brake and runs back to town. She discovers Doc's model of the time machine and rides after him. Having stolen the train at gunpoint, Doc and Marty begin pushing the DeLorean along the spur line, attempting to get it up to 88 miles per hour. Clara boards the locomotive while Doc climbs towards the DeLorean.
Marty arrives on October 27, 1985, escaping the powerless DeLorean before it is destroyed by an oncoming freight train. He discovers that everything has returned to the improved timelinebeloved home of 40 years on the Somerset Levels.

She set up camp on her first floor and even when the murky water began to climb the stairs was determined to stay. She called 999 only when her power went and she could not make hot food or a warming drink.

Now recovering with relatives away from the Levels – which are likely to remain flooded for weeks, possibly even months – Mallows does not know when, or if, she will see her farmhouse again. "It's going to take ages for this water to go down. Quite where I go from here is a mystery to me just now."

As the photographers, film crews and reporters pack up and leave following a week and a half of dreadful weather that left