Draw reins are not the answer. First I would have her teeth checked to make sure there is nothing causing her pain. I'd also have her back and feet looked at. Rooting and evasion can be caused by pain in other areas besides the mouth.
Once she checks out physically, try using a three piece bit on her. She may not appreciate the nut cracker effect of a single joint snaffle. Try a french link or bean mouth Full Cheek or D-Ring and see how she does. Or a Full Cheek that has a copper roller in the middle (one of my favorite bits to try).
When she avoids the contact, raise your hands up a bit, keep them soft, and push her forward into the bridle. Be sure your arms and shoulders are relaxed, not pulling, bouncing, or stiff. When she accepts the contact, drop your hands back down to a normal position and tell her "good girl." Rinse and repeat until she quits her silliness.
If she doesn't quit with the new bit and healthy mouth, try a Myler low port snaffle with a forward tilt. She might just not like tongue pressure in general.
I also agree, take things slow! You can't expect her to jump right back into the same routine you had before. Give her plenty of days off, spend some time on the trail letting her stretch and relax, and give her plenty of walking and loose rein trotting for warm up and cool down.