House would be a little young. Fred Nats players are mostly 20 and 21, and have either an extra year in pro ball, like Jordy Barley at SS, or, like Darren Baker, have some college ball.
That's judging from their roster: https://www.milb.com/fredericksburg/roster
That is helpful. I just wonder what the precedence is for guys who are superstars. I looked up the star of stars Mike Trout and see that he played 39 games in the arizona rookie league where he hit .360 but with only 1 HR before being called up for the last 5 games of the season in Low A the year he was drafted. Royce Lewis in 2017 and Manny Machado in 2010 followed similar paths. I didn't look up too many more, but it's certainly not unheard of.
It would not surprise me to see House get a cup of tea in Fredericksburg at this rate.