S.K.
I got my daughter her own baby doll, when i was having my son (they are 23 mos apart). when i would feed him, she would sit next to me and feed her baby - i bottle fed, so she was using a bottle to mimic me. we changed diapers together, she either used her doll, or she would hand me the wipes and diaper for her brother etc. i tried to include her in whatever i could with her brother.