I had my second child ten months ago. I have two girls. I wasn't necessarily interested in having a shower with my second child and was like you - worried that it was not proper. Well, my friends and family prevailed. My cousin threw me a shower and told everyone that I didn't need clothes since I was having a second girl. My girlfriends, because they can't resist the cute clothes, bought some anyway. Most of what they bought were diapers and wipes. They also each made a casserole, which we froze and ate them when I came home from the hospital. That was absolutely wonderful!
Our church also wanted to do something for us. They had a "diaper pounding" and anyone that wanted to bought us diapers. That was as great as the casseroles! I don't think we bought diapers for her until she was over six months old. It was great! When we finished a package of diapers, we just went in the cabinet and got another package out. I loved it! We live out in the country and if we run out of something, it's a trip to town. Having all those diapers was a blessing one night when we realized we had used our last diaper. :-)
Some people may not want to participate because they don't think it is "proper." That's fine for them. If your friend feels that way, she can do casseroles and a diaper pounding for you and your husband. The couples shower idea is great; it lets your husband be a part of the fun and gift-giving before the baby comes.
Let your family and friends celebrate your new blessing. You enjoy the celebration and don't feel a bit guilty about it!