Guess it depends on a few things. Whether she settles in London with a new-born, gels with teammates and enjoys the league and club, enjoys the winter weather etc.
None of that will be relevant to whether she stays another season or not.
If she stays another season will purely depend on whether the Womens Soccer League in States restarts next season after being cancelled this year due to the pandemic. That is only reason players are over here, and on short term deals, to get some football whilst the teams they are contracted to are unable to play.