You are going to struggle on this... Period.
Your family room is a place where people visit and see, and for most people, women most often, this room needs to be 'perfect'. As I grow older (43 now) I find myself looking at how I can incorporate the sound better with minimal impact on the room while making the room look better and better. But, it is difficult.
Aluminum low-profile speakers, TV on the wall, small subwoofer tucked away.
But, you aren't talking about that - you are talking about blocking a window which should have curtains and not leaving the mandatory distance between those curtains and a TV. No matter how I read that, it isn't something I would do in my home. About the worst I've dealt with was a home where the TV hung over the edge of the fireplace by about 2" on either side. I refused to recommend that TV to my client until they understood fully what that meant, and I installed a TV of the same size in another part of their home and then they swore they wanted that larger size over the fireplace. But, this was their bedroom, and the size was appropriate.
At the end of it all, it both of them who agreed to it and accepted the shortcomings of their home design which forced the situation.
Now, what choices do you have? You can't move windows. I assume that getting a smaller TV or one with a narrower bezel won't work either... So, it is a discussion which must be had.
For what it is worth as well, I have a client who is in the process of looking for a home. She emailed me and asked about TV placement over a fireplace. I explained to her about the issues with it (mostly bad) and told her that it was entirely up to her if she wanted that and she let me know that TV was important to her new home purchase, so it would impact her purchase decision.
Likewise, when I bought my current home a bit over a year ago, my wife said the following: "I don't care what you do with the A/V stuff, but I must be able to see the TV from the kitchen.
It's about 25' or so from the far end of the kitchen to the TV, but it's a clear line of sight, just as it was in our last house. I gave her what she wanted, and I'm possibly pickier than she is about where things go and how things look so it is a win-win for me. But, I bought my house knowing that this was important. The house would not have been acceptable to me if windows prevented the location to work, or if a fireplace was in the way (maybe). Instead, I have a 10' wide wall with no windows on it and no issues taking my 64" plasma up to a 80" or 90" display at some point in the future if budget allows. The room certainly supports it.
While I can understand being super stoked on your new home, the praise for the layout seems to be a bit off when it clearly isn't actually laid out to handle the TV you currently have in the configuration which you want. Awesome on the new home, but you have to give some serious thought to the aesthetics of your specific setup because you aren't talking about the 'big ugly speaker' on the floor. You are talking about a window and intruding into that space.
If it were me, I may stick with that setup if it works, but go to a smaller TV then find a different/better room for the bigger TV location. But, I'm me, and you are you, so I wish you luck in resolving the conflict and situation so you are both happy.
