Well lets see there is always fish that you can eat like tuna fish or sea food there are a lot of different types of sea food that you can eat as long as you are not allergic to it then you are good to go and it will be a lot easier since both of you are giving up meat for lent you can help each other out when ever feeling tempted.
My step mom, and dad are vegetarians! I'll help. You can by tofu, which has a LOT of protein. I really recommend eating lots of beans. And DO NOT eat ANYTHING from McDonalds, period. Glad I could help.