Rose I PM'd you but I will respond here as well.
Magoo never took Elavil but another pill and I never used the cream formulation. Sorry.
If her reaction is stress related then all the scruffing, towel holding to pill is probably making things even worse at the moment. Her experiences as an indoor kitty have not started off well, to say the least. After her attack she has been brought indoors and that has led to vet trip after vet trip, medication and more medication, conifinement, collars, and generally everything bad in a cats mind. Although we know the very best for her is being done, in her mind this has got to be an awful place! More stress!
My suggestion would be to continue with the Elavil. It will help her over time. She really does need this I'm sure. I PM'd you my method of pilling my "nasty" kitties but I will post it again.
Crush into powder and mix with jelly or a kitty vitamin paste (kill two birds with one stone!). Then rub it (hard) into kitties fur on her front leg so she can't shake it off. She will lick it off and get the meds.
Tell your MIL to make sure after she does this to give her lots of love and attention so she isn't afraid to be approached. Once they catch onto what you are going to do they can hide like Houdini! She will need lots of good attention inbetween the pillings so she will remain approachable.
These meds take time to work and I hope your MIL can be persistant and stick with it. I have no doubt that with a little time everything will work out just fine. Thats what everyone told me about Magoo and boy were they right! I sure do understand the frustration and aggravation though. It can be tough trying to help one of these kitties, but the payoff in the end is very rewarding.
Lots of luck and keep us posted.