Well, If the truck has no muffler (THEY ALL have an exhaust,, may not be the designed one but they all have it) Then talk to park management and have them suggest she pay a visit to Midas.
For general outside noise there is a very handy device installed in most RV's, both motor homes and trailers, which is a White Noise Sound masker.. Ok, so we do not call it that, but that's what it is,, This device will block or greatly reduce several sounds coming from outside if you have the windows closed.
And (Depending on the operating mode) it can also cool (or in some cases heat) the RV for you... Yes, I'm speaking of the air conditioner,, If you do not need heat/cool, turn it on FAN ONLY mode, on high
The noise (Many complain about it) is very quickly filtered by your brain, and when once that happens it masks sounds from outside, works well.
Next door to me it's a diesel Work Truck, they start out before First Light, and if I am awake I hear it, If I am asleep, I do not.. but then I lied 2 blocks off a main highway with nothing between my bedroom window and the Highway but the RV (not a lot of sound blockign there) Dependig on where the RV was you could see either the RV or the bedroom from the highway. (Well the window, curtains kept eyes out of inside)
