Hi Christina,
Just in case you weren't aware... It's probably not such a good
idea to burn joss paper, joss sticks, paper houses, etc.
But most certainly you can consider doing some meritorious deeds
such as giving alms to others, donating money for building schools,
temples, orphanages, libraries, hospitals, printing religious books
for free distribution and similar charitable deeds. Then,
dedicate those merits to your departed child.
Also, radiating loving-kindness directly to your child will be
helpful.
Perhaps the people at Poh Ern Shih can give you more advice.
With Metta.