Keep it simple. If you're more aware of whats going on around camp just coach your wife along. This isn't a complicated game she'll have it down shortly.
Every time a mob(s) come into camp, cast a low level root and get it slowed out first and foremost. That way you aren't going to immediately rip aggro off the wife with a slow and she's chasing the mob around. If you don't have mana to do this continuously, something is wrong. You're either over-buffing, over-healing, over-pulling, or a combo of all 3.
Regen is the 2nd highest priority. Both you and the monk should never be at 100% hp when things are going well (once you hit 24 and get Canni this will become very clear). Its the 2nd most efficient "heal" (slow being #1 by far and why its important to root + slow mobs immediately on pull). Play the game like the LAST thing you want to do is toss a direct heal on the monk. Let the Iksar racial, your regen, mend, and slow do the heavy lifting.
Haste for the monk is 3rd. Re-haste only when the other two higher priorities are being met. This shouldn't be an issue.
STR is a distant 4th and even more distant followed by the HP/AC buffs. Consider anything with a yellow shield spell icon pure luxury and only if you're swimming in mana.
Side notes: have your wife save her mend if she's unsure on a tricky pull...rather than using it on cooldown. Once camp is broken and things are smooth you can help her keep an eye on mend cooldown and make sure she is below 70% so you can get more max mends per hour. I know that may seem a little spergy but the more HP throughput she can offer the more mana you're going to have (remember: the goal is to cast as few direct heal spells as possible).
Its good to let her learn the pulling mechanics early on. Keep in mind roamers remain on the aggro table for a long damn time...even after she's flopped and they're off roaming around again. Sometimes the easiest solution is to /q while FD'd and reset...but you shouldn't be anywhere where this is a major issue right now anyway.
Save up and buy your wife Silver Chitin Hand Wraps (22% haste) and an
Imbued Fighters Staff. Aim to have this by low 30s level. She may not like the slow animation at first, but she will take significantly less damage due to fewer mob ripostes. This weapon will easily last her to 60. You take the rest of your cash for spells (you don't need all of them, just make sure you get your best slow and regen, the rest can be bought whenever you save up enough).
+55 HP rings, orc fang earrings, and a chipped velium amulet are nice bang-for-your-buck mend/str boosters too. Make sure you do all the looting and keep her under weight as well.
Some other monk gear ideas either for cheap for going to go farm them yourselves when level appropriate:
Syythrak Hide Vest
Drake-hide Sleeves
Shimmering Terror Hide Cloak
Silvery Mask
Monk Headband Quest
Gatorscale Legs
Black Panther Wrists