Lets get one thing out of the way - Ana is suppose to be countered by flankers. She should not have an easy time dealing with them, and giving her added mobility or a grappling hook is unlikely and would only add to the “mobility creep” of Overwatch, where slowly every hero seems to need to be mobile to be good.

Raising Ana’s HP to 250 would give Ana a critical extra moment to deal with a flanker on her own with her weapon. As of now, Ana relies way too heavily on one of the hardest abilities to hit in the game (sleep dart) which is on a massive 12 second cooldown. Giving her a small HP boost will give her a fighting chance if she misses and the flanker also trips up a little bit - It will give her another moment to hit the third shot required to kill a 200 HP hero like Genji, or a little more time to run towards her team if she is dove by a Winston or D.Va.

Alternatively, if sleep was made easier to hit by decreasing the start-up animation, her over-reliance on it would be considered justified in my opinion. That said, I believe the 250 HP buff would be a better option as it would allow for more opportunities for the Ana player to demonstrate their mastery of their weapon in a 1v1 with a flanker, rather than her survival completely depending on if she lands the sleep dart, that it isn’t on cooldown, doesn’t get eaten by Dva, doesn’t get blocked by a shield, etc.