Hiya! I don't have any kids but for Thomas, here are some options:
Alasdair Greyback is a little older and UC but he's very social so they might interact if Thomas is in the ~season scene. He's pretty easy going, doesn't want to make waves but likes to have fun.
Reuben Crouch is also a little older but MC. He has similar interests (Ex Quidditchers unite) but frankly he's a bit of a mess now, and has been for months, so not much fun in the friend department xD
And finally Fortitude Greengrass is slightly younger, MC, doesn't "get" Quidditch but is friends with other former Quidditch players (notably Cassius Lestrange) so that's not a deal breaker. If Thomas wouldn't mind someone occasionally going on nerdy rants about ghosts they could be friends.

Set by Lady!
Alasdair Greyback is a little older and UC but he's very social so they might interact if Thomas is in the ~season scene. He's pretty easy going, doesn't want to make waves but likes to have fun.
Reuben Crouch is also a little older but MC. He has similar interests (Ex Quidditchers unite) but frankly he's a bit of a mess now, and has been for months, so not much fun in the friend department xD
And finally Fortitude Greengrass is slightly younger, MC, doesn't "get" Quidditch but is friends with other former Quidditch players (notably Cassius Lestrange) so that's not a deal breaker. If Thomas wouldn't mind someone occasionally going on nerdy rants about ghosts they could be friends.

Set by Lady!