No. You shouldn't. You would go through proper legal channels so that the children would be removed safely and the parents would be charged instead of you being charged with kidnapping and the children being returned to that home. You can't uphold the law by breaking it.
The people on the Sea Shepherd show an indifference for the safety of not only the Japanese whalers but their own crew mates as well as well as a blatant disregard for law. And for those that disregard the danger to the Japanese whalers... violence begets violence. It isn't the way.