Mummies who didn’t sleep train: I need your advice!

Hi mummies who didn’t sleep train your babies, my baby is 3 months old and she tends to catnap in the afternoon. I usually have to carry her to pat/sway her to sleep before putting her on the bed. There are times she will remain asleep when I place her down, but most times she wakes up after 15-30mins and she will fuss and I have to carry to pat her again. Sometimes I just carry her for the whole 2-3hrs just so she can have a solid nap. I’m thinking is it because I didn’t sleep train and she needs me to soothe her to sleep that’s why she catnaps when she’s not in contact with me? Is this a concern? Do they grow out of it? Is there a need for me to sleep train her (I tried doing so but she always cry so hard so I end up carrying her instead)?