I'm quite slim and it took around 18 months for my tummy to get back to normal after DD#1 and that's not doing any exercise, so there is hope for you yet!

I've still got some loose skin after DD#2, but this time I've joined a gym (it opens next week!), so I hope it'll go back to normal quicker because of that! I'm also 9 years older, so I know my skin isn't as stretchy as it used to be!