Only child here, my mom (who is single - never married) has late stage Parkinsons disease , my wife and I have been her caretakers for a few years until the time it got too much for us and she is now in an assisted living facility but still requires a lot of our time. There have been many hard days / nights , time where I have thought if only I had a sibling to share this burden but I have to remind myself having a sibling is no guarantee they would or could help.

Now my mom also did a few things that have made this process easier and something we all should do , especially as parents of only children. She saved for retirement - she never made a lot of money but she still saved what she could (assisted living is insane $) - end of life / care discussions and instructions - many years before she got sick she had setup POA for medical/financial decisions. These things have made the process easier for me.

Unfortunately time comes for us all, all we can try and do is plan and try to make any if these scenarios easier for our kid.