Nicole,
Firstly I just want to say sorry for your loss and difficulty in TTC. In addition, I am sorry to hear of your sister being so unwell.
In relation to your question, if it were me I would continue to do what you are doing. When you do fall pg it will be at the right time regardless of what is going on in your life. Falling pg might cause a temporary shift in your family's way of looking after / rehabilitating your sister, but it won't be impossible for them. Situations have a way of being worked out.
In relation to being prescribed Clomid - it could go either way, you fall pg straight away as did my gf or be like me & just finished round 5 & no pg. If it is the later for you (I hope not), then I hate to say it, but you will be into your 17th month of TTC
Whatever you decide to do, best of luck to you & your family.