My dad is undergoing chemo currently so I have no experience with surgery but I know he’s very nervous about all of it. I think the best thing you can do for your mom is just be there for her. I bet just having you around is reassuring and will help take her mind off of it. It’s such a sucky situation with very real fears but unfortunately so much is out of our control. I’m thinking of both you and your mom and praying surgery goes perfectly without complications!! Keep us posted!