My strong, but not strong horse ?! help please!

[xoxellaxox]

Ok so I've had my lovely mare a month now. First of all I've had her teeth back and saddle all checked and no problems there . She is bomb proof out hacking . Nothing scares her and she fills me with confidence . Only thing is , she doesn't stop ! So at junctions im leaning back , putting weight in the saddle and asking her to stop . She just carries on . If I ask her to trot that's no problem. Just bringing her back to walk is ! I've noticed she crosses her jaw and pulls very hard against me .I ride her in a Fulmer snaffle as she's only 6 And it helps with steering . Anyways I thought I'd practise stopping in the school . To my surprise in the school she is sooo soft in her mouth . Not strong at all . Hardly any pressure on the reins and she comes back lovely to me. Totally stuck now . Any ideas about stopping her hacking is greatly appreciated !

 

[Pearlsasinger]

I have a very strong Draft horse, who schools very happily at home (we school in the field) in a NS Tranz, which is essentially a French ink snaffle but is strong out hacking. She had run off with her previous, novice, owner. I ride her anywhere but at home in a NS Universal with 2 reins. This is very effective because I don't need to pull and lean back.
With your horse I would find a more effective bit but you might prefer to use a grackle noseband, to stop her crossing her jaw.

 

[Princess Rosie]

Myler combination bit is fantastic for giving you brakes and you need the tiniest of squeezes to get results, my v strong mare went through pretty much everything between her previous owner and myself and the myler combination has worked amazingly and she loves it, it's a very kind bit (but obviously like any bit, only as kind as the hands connecting to it!). x