I just wanted to know if there's anything wrong with what I am doing here.

On my off-gym days, rather than just doing 1 hardcore work out, I break it up. So, for example, an hour or so ago I did 3 or 4 minutes of working my hiney, then, just a couple of minutes ago, I did 3 or 4 minutes working on my arms, with my dumb bells.

I am a stay at home mom, both kids are in school full time now, so I have time, and breaking it up 1) keeps me more motivated to do it and 2) occupies some of my time during my very quiet days.

Is it ok to do it like this? Or is it really better to do it all in 1 hardcore work out?

if you are really getting your heart going during the spurts of activity, it could be better than doing it all in 1 workout. to keep your metabolism going throughout the day. my problem is always i forget to do the rest of the workout spreading it throughout the day. but the best exercise is the one you want to do. keep the habit going, being consistent is what's most important.

I think its better to do it all together since it keeps your heart rate up for longer, and requires your body to put in more effort to cool you down thus burnings more calories but something is better than nothing and you will still see some results from what your doing. If your happy with the way your doing things then stick with it.