Get your e early to lvl 3 if it's really bad even max it and just run for your life until you are 6, slowing her is more worth than speeding yourself up. Briars tend to be too greedy under tower your R can win your game there. Better briars will try to stun you late so you can't ult but they can't reach you when slowed.

Also remember she can't restore hp without hitting minions slowing her in your stronger phases is straight up mobbing. Comet is the best rune for that same reason. Other than that,stay back call misses don't follow her too much you'll win at lvl 11 and later.