娘心(むすめごころ)girlish mind, girlish innocence

おじさんには娘心(むすめごころ)は理解(りかい)できないでしょう。

It's likely that an uncle can't understand a girlish mind.

夫(おっと)が必死(ひっし)に娘(むすめ)の娘心(むすめごころ)を理解(りかい)しようとしています。

My husband is desperately trying to understand our daughter's girlish mind.

４０代(よんじゅうだい)になり、もう感(かん)じやすい娘心(むすめごころ)は持(も)っていない。

In my 40s now, I no longer have a girlish mind that is easily affected.

好(す)きな人(ひと)に好(す)きだと知(し)られたくないという娘心(むすめごころ)を微笑(ほほえ)ましく思(おも)う。

I find it endearing that she doesn't want the person she likes to know that she likes them, which is a reflection of her girlish mind.

娘心(むすめごころ)をバカにする夫(おっと)の姿(すがた)を見(み)て、夫(おっと)への愛(あい)が完全(かんぜん)に薄(うす)れてしまいました。

After seeing my husband mock my girlish innocence, my love for him completely faded away.