Is using 的 for this correct? It sounds far too personal to warrant needing 的? Would 我爱我妈妈 be a better structure?

I love my mommy

When I typed in "I love my mother" it said that another correct solution was "I love my mother, which is strange.

In another case "我爱我的弟弟和妹妹" was not accepted; the accepted version was "我爱弟弟和妹妹". The lack of consistency can be confusing to me but probably to others too.