Minimum child ages allowed for travel

A past passenger of mine called me yesterday looking to book a new cruise for this summer. She hadn't been on a cruise for awhile as she'd just had a new baby so after I'd congratulated her and swapped some sleepless nights horror stories we got to talking about who she could cruise with. Her baby girl would only be five months old at time of travel and she hadn't realised this would be too young for many cruise lines.
It's with this in mind that I've wrote todays post, giving you all the minimum child ages need to travel with the different cruise lines. I hope you find it useful. - As a quick guide, if you are traveling with a child under six months MSC seem to be your best bet, especially as they normally give free child places aswell!