At 4 months, a baby typically can hold his/her head steady without support, and at 6 months, he/she begins to sit with a little help. At 9 months he/she sits well without support, and gets in and out of a sitting position but may require help. At 12 months, he/she gets into the sitting position without help.

Is it OK to sit a 3 month old baby?

You may want to wait until your baby is closer to reaching the sitting milestone to use a baby seat. Instead of propping your baby at three months old, consider waiting until sometime between 6 and 8 months.

Do babies crawl or sit up first?

But it's likely your baby will practice at least one before taking the plunge (Adolf et al 1998). Do babies have to sit up before they crawl? Once again, the answer is no. Babies can begin belly-crawling before they have achieved this milestone.