I am sorry that you have been waiting for a response. I recently just logged onto the site and noted that your question hasn't yet been answered. I am a licensed veterinarian with over 25 years’ experience and would be happy work with you if you are still needing assistance.
I would not recommend that you wait that long to have her cleaned up and evaluated. Sometimes, especially if the hair is a little longer, it can form a mat at the anus and actually lead to constipation or severe skin irritation
I am not sure that you need to have a vet evaluate, and perhaps a groomer could, but if she is irritated at all, may need sedation the area better examined. For this, it would be best to deal with a vet.
You do have a couple of choices. You could perhaps call your vet and let them know that someone other than you were going to bring her in and then find a friend to help. Maybe even one of their techs would pick her up. Your
other option would be to have a veterinarian that makes house calls examine her. I would think the first would be easier for all involved.
I hope this is helpful. Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please reply so I can clarify for you.