Mark the area where shot took place for reference with orange tape. Its handy to look back at that point of impact as you search further out for other sign. Then work in the direction she saw it go.
If you find blood mark that spot. It will give you line of sight and a good direction to proceed. Be careful to stay off blood markings. You loose the trail then look in a zigzag pattern from your marked trail.
Still lost go back to your last confirmed finding and take your time. Deer can leap quite some distance.
If you have any buddies with blood tracking dogs I also recommend that.
But take your time.
JW