I like her, (softkiss) but she sometimes is a bit out of reality. I believe she owns Chewy, a large male coastal, and Jade a large female. I don't think Chewy is 14' or the weight she says he is or he would be the largest recorded coastal carpet. However I think she is very passionate about her snakes and gives everything she has to them. Shaking could be a number of things. If there is ANY Jag in the genetics, neurological issues are common and normal. If the snake is loading up to strike food, a little shaking is also common. My boa looks like he's having a nervous breakdown before feeding when he is really hungry.
"Get a vet" isn't something I'd rush off to do unless you see other signs like mucus coming from the mouth, bubbles or some type of labored breathing. If the snake is constantly "stargazing" there could be some serious issues.
Is there a way to better describe the shaking? Does it exhibit cork screw movements, which are closely related to the Jag gene, but also IBD?
I'm certainly not a vet and won't discourage you from going if YOU think it is needed, however I do own a coastal carpet. She's a strange eater and only does some side to side shaking, more like swaying if I feed live. Otherwise she is very peculiar about food and will often slowly wrap and open her mouth for the frozen stuff.
Did the previous owner note any of these behaviors?
If the snake is eating, shedding and properly thermoregulating without constantly soaking, stargazing or making strange noises things are probably not critical. Keep an eye on things and keep us posted.