you can get full tier 9/10 (9 i think, maybe 10) just from the emblems that you get for completeing heroic lich king dungeons.
my 80s all wear the vendor stuff, item level average about 232, highest is 264 with a few 245.
hes my DK, probably has the beter stuff atm
http://eu.wowarmory.com/character-sheet.xml?r=Darkspear&cn=Sálazaar
Cloth armor vendor in dalaran will vend the Priest class gear for probably about 50 emblems of triumph each. And there will be item level 245 helm and spaulders available from the emblem quatermasters in dalaran.
silver covenant if you're alliance, sunreavers if you're horde.
If he does the dailies to get them I could see it being worth it. But how fully geared are you talking? Like...newest of the new? or like naxx 10 gear?
naxx10 gear is item level 200, for ICC groups you usually want average ilevel of acout 232/245.
now we use 'gearscore' addons. '5k' is usually minimum.
The emblems (
http://www.wowhead.com/item=47241#currency-for) drop 1 each per heroic boss you kill. the first random heroic you take per day will give you 2 emblems of frost (
http://www.wowhead.com/item=49426) for completing the dungeon, aswell as one triumph per boss.
Frost are redeemable for the much better class gear (item level 264, equivalent to icc25 drops).
Minimum of 5k Gearscore for ICC 10 man....it might be hard for her to get in unless shes more like 5300ish
25 man ICC = Forget it. 5500 GearScore Minimum
With 4.8k - 5k GS she could get in TOC 10 and 25 man but thats about it. Even TOGC 10 and 25 requires lower to mid 5's
ontop of the usual GS whoring, groups (PUGS anyway) will want you to link your achievement, because they want you to know the tactics. this is why a good guild is usually very neccessary.
in concluding my essay (sheese i play wow too much) ill say this, find yourself a tank or even a full group if you can, with good dps, healing and compitent tanking, and farm those heroics like theres no tomorrow. can do 400-500 emblems i na few hours. I geared my DK (linked above) from 2250 gs (level 79 blues) to 5080 (my current epics) in around a day.