Claiming severance pay bonus while on medical EI?

I have been on medical EI for about 3 months, and as it’s ending next week and I’m feeling much better mentally and able to return to work, I was supposed to Monday although my boss let me know that due to financial concerns on their end they are eliminating the position entirely. I am ok with this as I’m being laid off so I can go on EI.

Out of kindness she said she wanted to help me and sent me a sort of “severance pay” bonus of $1600. It was e-transfered to me via the official work bank account.

If it’s just a gift, although from my work, do I need to claim this? The whole point of this is to help me and be a gift, not money for hours I worked, so I don’t really want to lose the money by claiming it but I really don’t get how this works. Do I send it back to her?

I should note I would be applying for regular EI right after my medical EI ends on the 14th.