So, back story to all this (sorry a bit long). Two years ago, I had a line manager for 3 months. I'd just applied for a new internal post when she started and I'd been effectively without a manager at that point for over 6 months and had been covering for all the extra work. We had a bit of a personality clash and I also realised she already had an existing opinion about me (not a good one). She was my manager just when my annual review was due and, wow, what a review! It was the worst one of my working career and just a whisker above poor performance (which would have attracted a whole load of interventions and senior management involvement). It was frustrating because I'd worked my arse off for the previous 6 months undertaking higher level work due to the lack of a manager and she completely ignored that. I was close to putting in a grievance but didn't because I had my new post ready to go and figured that no-one would need see that review since I'd probably stay in my new post long enough to have new reviews, and also she wouldn't be my line manager any more so best not to make a fuss.
Any way, I've been working on a couple of projects with a new senior management person (who also happens to be the supervisior of my old line manager). She's been delighted with my work which is great. However, after a couple of drinks after work, she let slip that my old line manager completely bad mouthed me to her when she started a year ago. She told her I wasn't much good (I'm actually far better qualified than she is) and that I always make excuses for not delivering! I've since realised that she's been spreading this around other colleagues which I find very upsetting and unprofessional - and just mean and vindictive.
Now, I've just got a new job in another organisation. However, my old line manager (the gossip merchant) works closely with this organisation and her department is funding a couple of projects in my new organisation (thankfully not in my department). I'm now really worried that she's going to bad-mouth me to my new future employers. That's the last thing I need in a new job when you're trying to prove yourself.
WWYD? Should I confront her? Any other more smarter or strategic options?