Is my high backed booster fitted correctly?

[LoveBeingAtHomeOnMyOwn]

Ok so have no experience of booster seats. Just bought a new one for dd and went for a graco highe backed with side impact, the back can be removed if needed for the future.

So as we didn't have my car with me when we got it from halfords they didn't fit it. Dh and j have read the instructions and fitted it as described. However there us some movement of the seat. I am thinking this is probably correct as it can still be slightly tilted and afterall the seatbelt will be across dd and the booster and therefore keep her safe. My mum is completely disgusted and thinks it's fitted completely wrong, dh has now started to doubt it.

So wise and experienced car seat users please tell me who is right?

Booster seats don't really need fitting as a harnessed seat does but if you have very sculpted seats (i.e. not flat) the seat may wobble about or if the seat foam is very soft.

How does it fit with your daughter in? Does it still wobble even with her weight in it and her belted in?

Does the seat actually fit her - is she over 15kg (pref. 18kg though) and sensible enough to be booster trained (does she realise she is now responsible for keeping herself safe in the car not you?). Does the red belt guide come 1cm above her shoulder or is it higher than that with the belt crossing her neck/throat?

If those things aren't met (the seat wobbles even with your DD in it, the belt goes over her neck, she wriggles in the seat or slips the belt of her shoulder, etc) then the seat doesn't fit and should be returned if possible.