Is it safe to do boxing 2 months post-partum? If not, what cardio exercises can you recommend?

Wouldn't think so. Give your body time to heal. I went back to intense workouts at 3 months post-partum and got a pelvic injury that led to other injuries (strained adductor, hip tendinosis). Still doing physical therapy for those injuries and my baby is already a year and a month old! Try yoga or walking :) Take it easy.