A few months after Luna Caden underwent surgery to remove a grapefruit-sized cancerous tumour, her parents David and Monica pondered how to mark their daughter's second birthday.
Luna was still having chemotherapy and unsure what her condition would be, they approached the date with trepidation. They were delighted when Camp Simcha offered to host a party, arranging everything from the cake to entertainment.
"We wanted to do something - we wanted to celebrate her being alive," Mr Caden recalls. "They took the problem off our hands and made the decision for us." It was just one example of how the charity helped make an agonising time slightly easier.
Now three, Luna is in recovery.
The Hampstead couple were contacted by Camp Simcha after a friend passed on their details. Invited on its summer retreat, held the day before Luna's surgery, Mr Caden was grateful for the distraction. Luna was entertained by volunteers while Mr Caden and his wife were dispatched to a candlelight dinner.
"When you go through something like this, you focus purely on looking after your child. So when we got to the retreat and they took Luna off our hands, our initial reaction was to be a bit scared.
"But it was wonderful. Without it, we would probably have been at home worrying. As a thing to do before surgery it really helped."
As well as the retreat, there have been Chanucah parties and other events. Camp Simcha also arranged for Luna to have "big sisters" to babysit and generally be there for support. "She's now had three - they have all been wonderful."
The Camp Simcha experience had been wholly positive. "They are not intrusive and they understand what families want and don't want. No attention is spared. They could not possibly do more."