High-backed booster vs regular booster

[Aliviasmom]

Super quick background:  My mom has custody of my daughter currently.

My mom is allowing my daughter to choose between a low-back booster and a high-back booster.  I don't want her in anything but the high-backed booster....which is why I bought it in the first place.  Alivia will be 7 in November, but is only about 40" tall and is about 43 pounds.  She didn't transition into a booster in general until after she turned 6.  When I say anything to my mom about this, she says that Alivia's doctor said it was okay.

Please point me to valid information proving that high-backed boosters are safer!  (We live in Wisconsin, if it matters.)  Or is this not worth a battle?  Am *I* wrong?  Is she just as safe in the other booster?

ETA:  The car seat I want her in is the Graco Nautilus.

Edited by Aliviasmom - 10/27/11 at 2:00pm

[chickabiddy]

There isn't much evidence either way.

I personally prefer to see 7yos in high-backed boosters, but it isn't an issue I'd press, especially if your mother has the legal right to make the decision.

[jocelyndale]

Does the belt fit properly and does she have head support in the seat of the car itself (headrests, for example)?

[Aliviasmom]

Originally Posted by jocelyndale 

Does the belt fit properly and does she have head support in the seat of the car itself (headrests, for example)?

Yes.  But she is more apt to sit properly in the high-back booster I have for her than the regular booster.

[chickabiddy]

Okay, then that's what you should argue.  If she cannot use a backless booster properly, she is not safe in it and needs a highbacked booster.

I just read your ETA in the OP.  Do you want her in a harnessed seat or a highbacked booster seat?

[Aliviasmom]

High back booster.  The Nautilus makes sure the seat belt is in the proper position on her, and keeps her where she should be.  (Even if she falls asleep, she is still in the safest position.)