The 19-year-old goalkeeper made her debut appearance for United during the 2018/19 Championship winning season and had been out of action for the majority of the 2019/20 WSL season due to injury.
Blackburn will play in the FA Women’s Championship this season after they were promoted in May.
Casey Stoney said:
“Fran is a fantastic young goalkeeper with so much potential; this loan move will be really beneficial for her development. Blackburn were promoted at the end of last season and having had a previous loan move in the Championship with Sheffield United, I know that Fran can add some experience to their team and most importantly get minutes on the pitch.