When you have kids you should put your things in high places.
When you have children you should put your valuables out of their reach.
直訳で言えば When your child is born you should put your valuable things in high places となりますが、もっと単純に When you have kids you should put your things in high places とか When you have children you should put your valuables out of your reach と言えます。out of reach というのは手の届かない場所、という意味です。逆に within their reach ですと「手の届くところ」「手の届く範囲」という意味になります。なので keep your valuables out of your children's reach というと「大事なものは子供達の手の届かない場所に置きましょう」となります。どうぞご参考に。
Once you have a baby, you need to put things up high where they can't reach them, so they don't choke on them or break them.
この場合、次のような言い方ができますよ。
ーOnce you have a baby, you need to put things up high where they can't reach them, so they don't choke on them or break them.
「赤ちゃんが生まれたら、喉に詰まらせたり壊したりしないよう、物を高いところに置く必要がある」
to put things up high で「物を高いところに置く」
to choke で「喉につまらせる」
ご参考まで！
日本 
カナダ 
