since rampart will get her heirloom in season 10, should i smurf for shards?

I wouldn't do that, it might take you a lot of time unless you get really lucky. I do not think playing bad has anything to do with it either. I got my heirloom when I was about level 40, and certainly I wasn't playing bad. Not intentionally anyway. Besides, what if Respawn decides to make finding shards easier somewhere down the line? Yeah, by then you might have wasted a lot of your time for nothing.