Whats the best way to level with a friend who just started?

I'm a lvl 31 BRD but haven't played in about a year so I'm totally out of it. She is level 5 at the moment and started in Uldah (I'm from Gridania).

Should I start a new class and level with her? I can't do the story quests with her so would that be pointless? Should I remain lvl 31 BRD? Will I get level down for quests? Should I just wait for her to get to where I'm at in the main quest? That could take awhile. Not really sure what route to take here.

On a side note, if she wants to do some power leveling when there is down time in between story stuff in order to catch up to me more quickly, whats a good way to go about helping her level quickly?

Thanks!

You're going to have to level to 15 pugilist anyways for Bard, so you can always do that, you won't delevel for quests and they'll have a lot of zoned quests where they have to go solo. However, luckily you should still be able to delevel for fates, guildhests and dungeons, also in addition if you have a higher level you get a 50% exp boost to lower levels, so you should keep up with their quest experience.

Swap to an alternate class. You can level all classes on one character, so start training another! If you didn't touch PGL or LNC (I forget which BRD required), this is a great time to do so. If you're close to her level, you'll be able to share all exp on kills; whileas if you're too high level compared to your friend, neither of you will get EXP for most things.

Content that does level sync you, and thus can be played as any class of minimum level? That would be FATEs and duty finder. When you do those, do whatever you want!

Your friend shouldn't worry too much about powerlevelling - they'll need to complete story events to catch up to you regardless, and that'll give a hell of a lot of EXP anyway.

Agreed with the above. If you don't have Lancer leveled high enough for Invigorate, that's a skill you'll absolutely have to have cross classed to Bard (especially at end game) so I would make that the priority.

Otherwise if you already have LNC leveled for Invigorte, then if your friend is a THM then I would consider leveling a tank or healer... you'll be able to get fast queues together that way rather than both queueing as a DPS, and as they're fighting stuff in open world like with hunting log and fates you can either take over aggro as a tank or keep the two of you alive as a healer. If they're leveling gladiator however, then I would suggest leveling a healer. I would suggest Arcanist except for the fact that you can only be a DPS class until you unlock the Scholar job at 30, which also requires Conjurer up to level 15 to do, so if going with a healer I'd just pick Conjurer at this point.