I know this wasn't an easy decision to make, and it's natural to worry about decisions like this after we've made them. But unless God clearly directs you to bring her back into your home, you should assume you have taken the right path.
After all, the real question is this: What is best for your husband's mother? You love her, and you want her to get the best possible care during this difficult time in her life. You mention in your letter that she was beginning to need care around the clock, which is very hard for someone with a family to do on their own. If the Alzheimer's unit in this facility can give her better care than you could at home, you should not feel guilty.
The Bible says, "Honor your father and your mother, as the Lord your God has commanded you" (Deuteronomy 5:16). As I have said before in this column, this means not only honoring and respecting them when we are young, but also taking care of them as they grow old and need our help. The key is to seek God's wisdom so we know how best to do this.
At the same time, don't neglect your husband's mother now that she is no longer with you. Sadly, this happens far too often with nursing homes which is tragic. Even if she doesn't seem to know you, she needs the comfort and assurance only you can give, and she also needs someone to monitor her care.