Severance offer, what should I ask for? - 3 months and counting

I was offered 14 weeks of severance after 14 years as a data-entry clerk, and I have a few days to sign. It has been a long 12 weeks. There is a non-disparagement clause. Did anyone negotiate and succeed?

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

Ask for the offer in writing and do not sign on the spot. A day or two to think is normal.