While I think it unfair of her to "co-host" and not pull her share of the weight, I labor under the motto, "don't expect anything and you won't be disappointed." That little saying has gotten me through a number of situations, including a live in BIL who stayed for 2 years, 3 months, 5 days, 11 hours and 34 minutes (but who's counting) and did nothing.
M