Thank you for the insightful replies mummas! Ive been told as long as their knees sit at the bend of the chair and the seatbelt sits at the right spot across their chest, shows a good indication. We have the booster already and have purchased the best and widest one thinking our girl would be in it longer, or at least up until 9-10 years old but she is just looking far too big in it, and even with the straps at its loosest, she still finds it too tight and restricting. Might be time we say goodbye to it! So bittersweet knowing theyre growing up

My kids all were sitting comfortably on the back seat of my car in their seat belts by the age of 8, I followed the instructions from the NSW Government Service NSW said a child 7 and over can use a seatbelt if they meet the height requirement of around 145cm. Sitting with their back into the seat properly and the seatbelt fitted properly. I did buy sheepskin wrap to make sure that the seatbelt was adjusted lower for a child. (See you car manual).

My youngest is 11 year old (turning 12 in 2.5 months) and I still have her in a booster seat, in fact I bought a new one this year. Like your eight your old, my daughter’s feet don’t touch the floor yet. What is your daughters height ? I think they should around 145 cm tall in order to discontinue the booster seat