There has been tremendous development in Nigara Falls Canada with lots of new hotels. End of April is still the slow time so rates will be lower. Lots to choose from. Not as much on the U.S. side but rates may be cheaper. No four-star places on the U.S. side
One popular area near NF is "Niagara On The Lake". Quaint village with interesting shops and restaurants and wineries. Not a cheap area and, if your kids are young, they may be bored. You wife will love it.
Toronto is about an hour away but the traffic can be a pain and Toronto has the cost of any big city. But there is a lot to do.
Buffalo is a half hour south if you want REAL chicken wings! (The Anchor Bar!) There are also some good museums (Science, Art, History, Aviation, Navel Park) and a decent zoo, but with recent county funding cuts, they are closed several days a week. Check out Buffalo.com
All of the tourist areas around Niagara & Buffalo are safe and it is easy to get around by car. Parking is always free or cheap.
One note, make sure you have copies of your kids birth certificates to cross over to Canada. (Unless they have passports.)
Finally, make sure to get a ride on the Maid of The Mist boat. GREAT ride and cheap! They should be in the water by late April. The lines are always shorter on the U.S. side.
Jim
"Only those who attempt the absurd achieve the impossible"