the next day I checked and I was able to access her account.Today I checked her page and its says this weemee is unvailable.Why is this?"

The account could be an account owned by WeeWorld, and they are disabling/enabling it to possibly test a new feature (they have done this before, with MileyAmerica, who randomly becomes available/unavailable).

However, if you know the account is owned by a real user, it could be that the account was temporarily banned while WeeWorld investigated a report against the account.

If the account is unpredictably changing in availability, try clearing your cache. Your web browser may be loading an old (unavailable) version of the webpage. Clearing your cache will force it to check for a current version of the webpage.