My bb also 12mth3wk, I'm also planning for 2nd b (now intaking the Folic Acid) but I still keep breastfeeding my bb.
Why not keep breastfeeding bb? My boy say "99" sweetly everynight to ask for sucking. This is a very treasurable moment and I'm very enjoy the bonding between he and me.
BTW, regarding the cheese, since my boy is under-weight, I frequently feed him yoghurt and cheese but the doctor advise me not feed him cheese so frequent coz the level of salt is too high for toddle.