Wait until your baby sits unsupported, usually by 9–12 months. They need strong...

https://www.bookmark-help.win/most-experts-suggest-waiting-until-your-little-one-sits-up-steadily-on-their

Wait until your baby sits unsupported, usually by 9–12 months. They need strong neck muscles for a helmet. Trailers offer the safest, lowest center of gravity for infants. Front seats work well for active toddlers, while rear seats provide stability