Shancai seeking knowledge Picture

The goddess is Guanyin, and the boy is Shancai.

Guanyin is a bodhisattva of Chinese (or now more widely Eastasian) Buddism. Usually the religious bodhisattvas do not have genders-that's why Guanyin's gender is unknown.

It says on Wikipedia:

It is generally accepted (in the Chinese community) that Guanyin originated as the Sanskrit Avalokiteśvara (अवलोकितेश्वर), which is her male form

During the Tang dynasty, it was very common to portray her with beards which indicates male form. But her appearance turned to female as time went, and today she is generally accepted as a female deity both in Buddhism and Taoism. In buddhism she is a bodhisattva, and in Taoism she is an immortal. She is known as the "Goddess of Mercy", and sometimes is seen with children in her arm indicating that she is also a goddess of pregnancy and new life.

The boy kneeling is Shancai, whose sanskrit name is "Sudhana". There are many interpretations regarding him, the only similarity between these legends is that he is one of the children guarding Guanyin.
The version I'm going for is from the story "Journey to the West".

In the story, Shancai was actually a demon who takes the form of a child. His name as a demon is "Hong Hai'er"(aka "Red Boy"), and he is the son of Princess Iron Fan and the Bull Demon King. He had developed True Samādhi Fire which no mortal water can put out. So Sun Wukong went to ask Guanyin's help, and with her pure water in her vase she defeated Hong Hai'er, making him her permanent disciple.

But mostly this is inspired by a song by an internet artist which is named "Hong Hai'er" . In the song Hong Hai'er and Nezhawere childhood friends, but when Nezha got his Lotus Form he forgets everything about their past. Hong Hai'er believed that this is caused by their difference in beings. Nezha is an immortal, and Hong Hai'er is a demon. So he decides to become Guanyin's disciple to seek for immortality.
The story which the song tells obviously shows the Taoist version of Guanyin and Shancai.

Chinese Ink&Brush
Continue Reading: Sun