Answer

By Your Horse

Dressage Rider and Trainer Claire Lilley advises:

I think a different noseband is a better solution than a stronger bit, but items of tack such as this should be seen as a short-term correction. First, ensure that your daughter’s riding is correct.
The Kineton noseband sits across the nose like a drop noseband, but instead of being fastenedunder the chin, it has a metal hook on each side that fits around the bit. When a contact is taken up, the noseband exerts pressure on the nose.
It can prevent the horse from leaning on the bit or grabbing at the contact. As with a drop noseband, or a hackamore, take care to fit the noseband across the bottom of the nose bone and not too low on the nose cartilage.
The Worcester noseband looks similar to a flash with a lower strap that divides, but instead of the strap passing under the chin, the two parts attach to each bit ring, holding them in place. When a contact is taken on the reins, the noseband exerts pressure on the nose. It can prevent horses getting their tongue over the bit or avoiding the contact by leaning. This noseband sits higher on the nose than the Kineton, and I think it would be most suitable in your situation.