Is there an age limit to applying for a tourist VISA to Hong Kong?

My friend's Daughter is coming with me to Hong Kong. However the problem is, I am a Hong Kong citizen but my friend's Daughter is a Myanmar citizen aged 15, a secondary school student in Singapore. She will be staying with me at my house in Hong Kong so I do not have any travel itenary or hotel itenary as part of the required document to apply for entry permit for her. So how do I apply for her?