Could you kindly check the grammar of this sentence?

Hi,

Could you please check if the second sentence is correct?

I had worked really hard for many days, running to multiple stores, making lists, and picking up ideas for my baby sister's birthday party.

I knew it was worth it when I saw the smile on her face as she bent down to blow the candles.

Or, should I write this: It was worth it to see the smile on her face as she bent down to blow the candles.