what can a Sikh girl during December during the time of the saaahibzaade shaheeds?

Dear one,
Waheguru ji ka Khalsa, Waheguru ji ki Fateh!

In response to your question, the undersigned wants to say that though the four Sahibzadas were of very young age but the Sikhs address them as ‘Babas’ because they had achieved a very high spiritual state They laid down their lives and died physical death but didn’t agree to die a spiritual death and became immortal for all times to come. You can remember the following two Saloks from Gurbani and sing them again and again, in their memory:-

ਜਉ ਤਉ ਪ੍ਰੇਮ ਖੇਲਣ ਕਾ ਚਾਉ ॥ ਸਿਰੁ ਧਰਿ ਤਲੀ ਗਲੀ ਮੇਰੀ ਆਉ ॥ ਇਤੁ ਮਾਰਗਿ ਪੈਰੁ ਧਰੀਜੈ ॥ ਸਿਰੁ ਦੀਜੈ ਕਾਣਿ ਨ ਕੀਜੈ ॥੨੦॥ {ਪੰਨਾ 1412}

ਸਲੋਕ ਕਬੀਰ ॥ ਗਗਨ ਦਮਾਮਾ ਬਾਜਿਓ ਪਰਿਓ ਨੀਸਾਨੈ ਘਾਉ ॥ ਖੇਤੁ ਜੁ ਮਾਂਡਿਓ ਸੂਰਮਾ ਅਬ ਜੂਝਨ ਕੋ ਦਾਉ ॥੧॥ ਸੂਰਾ ਸੋ ਪਹਿਚਾਨੀਐ ਜੁ ਲਰੈ ਦੀਨ ਕੇ ਹੇਤ ॥ ਪੁਰਜਾ ਪੁਰਜਾ ਕਟਿ ਮਰੈ ਕਬਹੂ ਨ ਛਾਡੈ ਖੇਤੁ ॥੨॥੨॥ {ਪੰਨਾ 1105}