Other than the seat, make sure you have belts mounted correctly. You want the belts to go through the seat even or on a little bit of an upward angle from her shoulders. I am 5'11 so my belts go through the seat and over the top roll bar not the middle one. You want the belts to be aligned correctly. You want the belts to hold her back not down, if the belts are pulling down on her that is no good and could cause spine injuries. There is no way to 100% correctly mount belts in a Legends Car so we have to do the best we can.
Sorry to chime in here, but I think I should. I know I'm new, but I'm not new to racing or installing racing equipment. A shoulder harness under no circumstances should be anchored more than 1”- 4”
below shoulder height.
Mounting below this height can and will most likely cause additional spinal compression during an accident. You DO want it to hold you down. Not so much that it compresses you, but you sure don't want to be able to move up at all!
That is on almost every single set of harness instructions I've ever seen. I've mainly used GForce, and never had to test them, but this is what they recommend.
Are you not allowed to use backing plates? I will admit I'm not familiar with the material inside a Legends car, but I do know, GForce makes a 4" backing plate that you can bolt through and it give more mounting surface then just drilling a hole and throwing a bolt through it. Is this allowed for you?? I would think, adding these plates for "safety concerns" wouldn't really be an issue..