FATEs are a good option, since those give a good amount of XP, even when your level is not higher enough to do the FATE (that's how i levelled up there, instead of doing challenges XD). Another option would be just not being in a party, similar to how some people levell up BLU; let her hit the mob(s) first and then help to kill them (to be totally honest, i don't remember if this works inside Eureka)