To my knowledge I've never heard of an attorney driving by a home to check on parenting time.  I think what she means is that she will have to calculate some numbers to figure what adjustment would be appropriate for summer parenting time.  Sometimes child support is adjusted based on an annual sum of child support amounts - if you have the kids for 3 months and he has them 9 months, child support would be reduced to 9/12 of the original number.  Or, sometimes child support will flip flop.  So you pay him for 9 months, then he pays you for 3 months.  Personally, I would request the later.

I hope that answers your question.

Read the child support guidelines as there are a couple scenarios I believe which assume summer parenting time.

So you are now paying $862/mo?  What would it have been without the adjustment?  Do you know how the adjustment was calculated?  I'm curious what the rationale was behind the $138 (if there is any).  This could help other members.

That number sounds a bit low.  When they are with you during the summer, are they with you 100% of the time?  If we say you have them for all of June and July,  you should maybe get a 2/12 reduction, which is $173.  Not sure why the number is low.  Did anyone tell you how it was being adjusted?  Someone should have that on file.