To be forward facing she should be minimum 15kg/33lbs, 4 years old and 110cm tall(all criteria's should be met) But if you want to turn around, absolutely get a high back booster seat. And look up internal decapitation.

NO BOOSTER!! Your child needs to be in a convertible 5pt harness seat. And if child hasn’t maxed out of rear facing limits then I would keep rear facing. Height max is based off of the top of the head 1” or more from the top of the seat. Leg room does not matter, legs are meant to bend and can go so many directions. 6yrs old at earliest for any booster seat.

She should still be in a 5 point harness car seat not a booster seat

Our forward facing 5 point harness car seat has a weight limit of 65lbs and 57” for height. My son is 40lbs and 38” and is perfectly comfy still in his car seat. We just turned him around to forward facing since he hit the weight limit. The big question for the switch to the booster is do you think she will stay put with just a lap belt.

I think she will still need a seat with a back. My daughter is still rear facing with more than enough room to continue so I'm not 100% sure but if you check out car seats for the littles they can help you!