Tell her whatever suites you & your wife at this point in time ! However remember & be prepared for same treatment when you are confronted with same situation later in your life when you are your mothers current age !! You are in the world today because of her !! God Bless !!!
Tell her that you love her very much but, that she needs to carry on with her life. Say that you and your wife want to be alone to talk about things that you won't talk about in front of anyone else. Tell her if you two decide to lay down together in the daytime you want to be free to do so without company being there.
Tell her that you both love each other and that you would like to take your wife to bed when the mood strikes. Tell her that you realize after a couple has been married quite a few years or has older children it has to be planned at night.
Tell her you don't like planning on being together at a certain time. Tell her that's why you got married so that you could do what you want when you want too without planning.
Can she live alone? Is she healthy? Is she capable? If so, help her find a place. Is she financially able? If you calmly discuss her options and offer to help her, it will go along way for your future with her. If she shouldn't live alone and you can help, find an adult community that she would feel comfortable in and help her move. Visit often and include her in family activities. Good luck!
Before you have this chat do your homework by having the options where she will be able to afford housing and get around..be ready to assure her how you will visit her often and still do things together as a family. You should be very aware of all the signs of depression that she may experience before and during this move...besure she can get some help, DR?..or has a support group, church, friends, ect to make it a good transition. If she doesnt have a little pet, really consider getting her a older small dog to keep her walking, feeding and taking care of something. Make an effort to have a special day or night that you and wife come to have dinner or have her over to your house. Plz try to make this an exciting and fun experience, even helping decorate or buy a special piece for the new home. Good Luck.