Can I Place a Memento with My Dearest Sister Before Her Burial?

Assalamu alaikum, I’m reaching out after losing my closest companion, my sister in every sense but blood, Soulaï. She passed away sadly due to mishaps from her cancer therapy. I’m not a Muslim myself. Even though I’m near to her family, I’m unsure about the burial rites and don’t want to trouble them with queries during their mourning. Her remains will be taken back to Egypt, and I was thinking if, according to Islam, it’s allowed to leave a personal token with her prior to burial. She’ll be so distant, and in my own manner, I wish to leave something with her so she won’t feel utterly alone. I know I’ll journey to visit her grave in Egypt at least once, but this is something that feels close to my heart. JazakAllah khair.