Eureka and level differences

My friend visited Eureka for the first time a couple of days ago and I went along with her. However we quickly ran into the problem of her not getting any experience points or challenge progress if we fought enemies together. The only thing I could do to help her was heal her, and even that wasn't really necessary. I guess we could have moved to a higher level area but then she'd have been powerless to do anything. Since she seemed to do just fine even without my heals I decided to hop on the FATE train instead.

She's level 10 now I think. We'll probably go there again at some point and maybe even get new friends to come along. What's the best way to play that content together? FATEs have level sync and start at level 1, although they are located in areas with enemies 4-5 levels higher than the FATE. They could be an option after the first few levels, but it still feels frustrating to not be able to offer meaningful help at the beginning. Is there anything else that we all could do together and benefit from it?

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)

From what I noticed about Eureka, even if you tag a monster and others help kill it, it can reduce exp you get - if not completely eradicate it entirely. At least, this is speaking from my own experience while I was leveling there and trying to get Challenge Log progress.
There's a level discrepancy threshold that, if passed, you get significantly less experience from a monster or FATE. I don't know if exp would be reduced if someone just purely heals you while you down the monster, though. That would be something to test.

I honestly wish they had a level sync for outside of FATEs, like they did on XI, where you could all sync to the lowest level player in the party. At least then, you could fight enemies 5-6 levels higher together, get Challenge Log progress, and still get a good bit of experience (plus chains) from the monster killing.

We tried not being in a party but she just got no EXP (nor challenge log progress) if I hit the monster. Heals did not cause EXP loss, but they were not really required either so it was very boring for me.

While doing the FATEs I noticed that Lv16 monsters still gave me like 1 EXP per kill, so perhaps that would be the limit where she'd also get credit while in party with me.