Supporting my sister

My nephew is 3 and was diagnosed with cancer in both eyes about 5 weeks ago. Since then it has been endless rounds of hospital visits, surgery, chemo and dashes to A&E. This may seem trivial but it's my sisters birthday tomorrow. I know the last thing in her mind is her birthday and we are all focussed on the little one. That said I would like to be able to offer her something that might seem appropriate and helpful tomorrow - a promise of something she could do when we are through all of this. I was hoping someone with the experience could share what might have helped, drawn a smile for them that maybe I can do for her also. Thank you xx