If you are asking this question, ur relation with her is obviously not great. As your husband's mother, she considers ur hubby and children to be 'her family' and not just 'yours' !
How often does she visit you ? If it's too often, it's time to tell your husband how you feel and let him talk to his mother. You guys would have to clearly tell her that you want a little more privacy at home and would appreciate shorter visit . It's not really possible to convey the message without her feeling bad about it.
If you don't want to talk to her like that, maybe you can remind her that leaving her house for such a long time may make it easy for thieves to get away with any valuables that she has .. Or tell her that you guys are going on a vacation and have already booked your tickets !