Should I negotiate my severance?, janitorial supervisor here

I was offered 13 weeks of severance after 13 years as a janitorial supervisor, and I have a few days to sign. I have read a lot of threads here and could not find my exact situation. There is a non-disparagement clause. What did you ask for?

An hour with an employment lawyer cost me a small fee and made me feel much safer about signing.

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.