It would be hard, especially since it's cold and you'll want to eat more to keep warm.
My advice:
1) Don't rush yourself. Train yourself with GOOD HABITS and the weight will melt off by itself, rather than pushing for extreme diets.
2) With a baby, you're bound to be more stressed. Make sure you have time each day to unwind and relax. Relaxation helps with weightloss. Stress does not! It would help if you learnt how to deal with your daily struggles in a calmer fashion.... Smile smile smile.
3) The only foods you need to avoid is pretty much carbs. I cut out pasta/potatoes/bread from my life and I automatically dropped 20 lbs in a few weeks. They are not kind to the female body. The only carb I have is rice because I love it. But I would definitely stay away from pasta and bread!
4) Don't be afraid of meats/fats. Eating them will help your body burn your own fat. With this in mind, I would buy full fat milk (I drink it all the time) instead of semi-skimmed. I would have a larger portion of meat during meal times, roasted/boiled but NOT fried.
5) Stay away from the salt!
Salt is everywhere. It's in canned food, instant food, microwave food, jars... salt will make you fat. Buy things you can cook/eat fresh as possible. Avoid cans of food.
6) Patience.
If you don't see results in the first week or two, this is NOT a good reason to give up on your diet. Read this, write this down and post it somewhere to remind yourself that even if you can't see anything different, does not mean you can go back to that icecream tub.