We are traveling to belguim to visit our daughter studying abroad in brussels.
Our plan is to meet her in paris on a fri morning and stay till sunday, travel back with her to brussels sunday. The question is should we stay in brussels and do day trips for the rest of the week, or stay a few days, then go to amsterdam maybe thur and fly out saturday. the trip includes my husband and kids, 16 and 11, and me.

Amsterdam is simply one of the most beautiful cities in the world and only 3 hours by train from Brussels - could even day trip there though better to stay. Gent, Antwerp and Brugges excellent day trips and Paris is about 1.5 hours via the high-speed Thalys train - London is just over 2 hours on Eurostar trains.

Coondog1217,
We (including two boys 16 and 13) just came back from 10 days in Amsterdam, Brussels and Bruges.
We didn't enjoy Brussels much but loved Bruges and Amsterdam.
When are you leaving? If you still here, I will type TOP 10 from both kids for you.

Since I posted this, we have changed our plans to Paris 3 days, Brussels 2 days, and London 4 days. If you have any suggestions, I'd love hear from you. We aren't going until Easter.
Thanks

Coondog,
I was going to say go to Bruges on the way to Amsterdam, its lovely. But frankly, it may not have the same charm as a day trip from Brussels as it seemed there were many daytrippers & the town really mellowed out in the evening. I hate to say, we enjoyed Amsterdam more than London, mainly because of the size of the city of London. Whatever you do, figure out the subway in London ASAP. These trips were with kids in tow, 16, 10 & 10.
I am looking forward to visiting the oldest when she goes overseas to college! Have a great trip.