I'd say it was 9-12 months before I felt my old self again. I put on 25kg and have (at 12 months later) lost 20kg. That pesky last 5kg won't budge but I'm not exactly trying and I feel so much better than I did 6 months ago.
I just eat smaller meals and snack healthily, and do a pilates reformer bed class once a week. And walk every day with the pram.