When my husband and I decided to build our house, we knew that we wanted to design our house our way and so we started with a floor plan and made the changes necessary to accommodate life as WE planned it. The original floor plan we decided that we liked had 3 bedrooms and 1 bath on the main floor. However, we KNEW that we were going to have about 3 years between each of our kids, so by the time our 2nd child needed a bedroom the first one would be 4 years old.
We designed our house with 2 bedrooms and 2 bathrooms on the main floor. Well, life has sure taught us that things don't always go as WE plan! Our first 2 children are only 13 months apart and our genders fall boy/girl/boy. So that means that there are only 2 bedrooms on our main floor to fit 5 people. I wasn't comfortable moving the 2 older kids downstairs until they were at least in school. That meant that our son and daughter had to share a bedroom for the better part of 5 years.
I'm one of those parents that is very matter of fact about things that embarrass some people in life. When my son has asked what a certain body part is, I tell him. When my daughter wants to know why she has different body parts than her brothers, I tell her. Our bodies and the functions that we are born with are very natural and absolutely nothing to be embarrassed about.
In our home, there is no reason for people to be ashamed about who they are or how they are made. Sharing a room is something that our children have enjoyed for years. While we did transition each of them to their own bedrooms this year, the kids learned how to play well with each other and learn how to share. Even though they had separate beds (2 toddler beds that then turned into a twin over full bunk bed), many times they slept in one bed. They enjoyed the security of being close to someone else.
They have now outgrown sleeping in the same bed, as we assumed they would do. However, it is what worked for our family at that stage in their lives and I would encourage each of you to do what works best for your family at this stage in your life as well!