3 month old activities

She's now 3. She nows plays by herself on her activity rug, or will stay quietly in her crib watching her mobile. I feel somewhat guilty to put her by herself once I've fed/burped/changed... I usually try to at least read her a book a day, give either a massage or a bath, talk to her and play for at least 30 min. Can't dance with her due to medical issues, nor baby wear. Any other ideas of plays or things to do with her?