Your opinion on what to charge?

I have been getting some "different" requests and am still a little unsure what to charge for them - so I would love for some advice.

This time I have someone who wants me to come by 1 time a day for a 30 minute or 1 hour visit. She has 7 dogs (2 foster dogs and one is pending adoption in October) so there would eventually be 6. The largest is 35-40 lbs. She has 2 girls who cannot be in the same room so need to always be separated (so I have to learn her system for moving them around). No meds or feeding involved. Just letting them out in the yard to potty, giving them attention and playing with them. She said I could walk a couple of them if I wanted. This would be a 3 time a week booking and a regular job. What would you charge in a situation like this? If I go by my normal fee schedule, the charge would be $45 for all 7 dogs (30 min session). Does that sound reasonable?