I remember when I was first starting out - I was so against fitteds and covers - but now - oooooh boy..... I love them.... its the only combo that I don't think - hmmm.... I wonder if this will leak..lol...

Plus if you get something like baby beehinds fitted - you can use them on both the kids (cos I do) and just have different sized covers

Although - I think the medium mother ease rikki covers would fit both your kids - cos they fit both of mine (DS is in a large too.. they have a great weight range)