We've never seen anything at the casino CG to raise a red flag. Not sure how often security checks etc. but there are other RVs around. Good for her to ask.
Our schedule changed and we were there today - read on. 1.5 miles to the border parking lot. $6 car, $8 RV (I think) and something about getting permission. The gate money collector said you can stay overnight in the RV - To be clear this is the border parking lot. Maybe that is a future option for us.
Walked in got the meds and out at 2:00, no line.
My hats off to DW as it's good to be concerned. There were several RVs on the north side of I-8 and don't know about that area.
I think there is an effort to make your visit there safe. I did see one armed (Mexican) person today and last year 2 directly across the US return entry with some big guns during my 45 minute wait.
BTW No doggies today and they ignore us anyway or maybe we just thing they do.
Got some meds today from the Purple Pharmacy, never bought alcohol from the Purple Liquor store but decided to buy a belt today. He said they are part of the Purple group. Who would know?