I put on 13 kg after my second child and haven't lost all the weight yet but am working on it.
I recently discovered youtube exercise videos. They have 10 mins videos to tone the body, stretches etc.
My child would try to join in as well. It is fun and quite easy to squeeze in 10 mins here, 20 mins there.
Diet is important too. Go high on fibre and low on fat.
It's easier to control one's diet if one cooks at home. Food outside tend to have too much oil, salt, sugar, MSG etc.
Check out some blenders, juicers etc at http://www.homegeeks.com.sg
More products are constantly being added, so do check back often!