EGR valve replaced, engine overheated and now has seized...help.

My mother is law has a 2001 Chevy venture which she was getting horrible gas milage
on and felt like it was loosing power when driving, so she had a diagnostics performed
which came back saying they EGR valve needed to be replaced. She had this done by a
friend (I know, I know but she's on a very fixed income) and after driving it for about ten
minutes, it started to overheat. She brought it home and they put water in the radiator,
and took it back out again after about an hour. It ran fine for about five minutes, but when
she got on the freeway it started to get hot, the battery light came on, smoke started
coming out of the engine and the engine went dead. The lights stayed on, but after
coasting to the shoulder it would not start back up. When she tried to turn it back on it
would make a sound like it was trying to start, but nothing would happen. The van has
since been seen by another shade tree mechanic who said the engine has seized. I'm
thinking about having it towed for her to a mechanic but if it seems like a lost cause and
that it is most likely correct Id be more inclined to scrap it and get her something else. I
would really appreciate any help. Thanks in advance. By the way, don't know if it's
relavent or not but we live in AZ and it was about 112 that day when this happened.
Thanks.