It would be lovely if the three of them get along well and play together in your house.
It would be very nice to see all three get along and play together in your house.
I'd be so happy to see the three of them play together in your house.
というのはいかがでしょうか ヽ(o´ω｀o)ﾉ
It would be lovely if the three of them get along well and play together in your house.
(あなたの家で3人が仲良く遊んでくれたら嬉しいです。)
It would be very nice to see all three get along and play together in your house.
(あなたの家で3人が仲良く遊んでるのを見れたら嬉しいです。)
I'd be so happy to see the three of them play together in your house.
(あなたの家で3人が仲良く遊んでるのを見れたら嬉しいです。)
以上、乱雑で申し訳ありませんが、少しでも参考になれば嬉しいです (*´ω｀*)ﾉ
日本 
