No, you're fine. We've openly told the kids we're selling the house when the youngest goes to college and buying a one bedroom condo
As a youngest, I know it would have been distressing to me to watch my sisters be able to come home from college and have their own rooms to stay in, and then to be told I wouldn't have that opportunity. When I go home now, I have to sleep on the sofa, and the lack of privacy is really pretty uncomfortable for both me and my parents.
Jocelyn, while I appreciate your situation, my response was both a little tongue in cheek and totally serious. We plan to help our kids out with college as much as we can, as well as start seriously preparing for retirement. When my youngest is 18, we will no longer need/want a 2400 sq foot 4 bedroom home, upkeep taxes etc. He will likely only be using it as a crash pad at that point anyway

(That's what I was doing at his age, I think I may have seen my family twice a week).
The tongue in cheek part was the one bedroom condo ( I will likely at least have a guest room

) . I am totally serious about my kids growing up and moving on with their lives and my husband and I moving on to the next stage of ours. At that point we will need to move all our family resources into saving for retirement. We will need funds for our retirement years more than a home for a family who should be becoming independent.
There are growing pains to every stage in life. My job as a parent is to raise my boys to be productive, self supporting, law abiding and of course, polite adults. Keeping the family home to be "fair" is not part of that equation. Life is not fair.
As the youngest child in your family, I am willing to bet that there were opportunities that you were given that your older siblings were not (i.e. in my family I was allowed to borrow a family car, but that car was sold and the money was given to my younger brother to purchase his first car. I was not given any money for my first car purchase). However, my younger brother also ended up on the short end of the stick with the family home. It was sold when he was 19 and in the service and he stayed with me when he visited for a few years.
So please understand while I don't plan to kick my kids out the door on to the street at 18, I really am looking forward to my empty nest years. Because, if we've done our job as parents well, we will have earned it.