Jumpseat is normal Ops for the two jump seats in the cockpit. There are a couple captains out there who aren’t comfortable with someone breathing down their neck and will deny, but they seem to be few and far between.

capacity in the back is limited so no one has to sit in a middle seat. Ops agent won’t put more on the plane than this capacity, plus the two jumps. Chances are good a family will sit together and you can still end up in back instead of the cockpit.