I've received some good feedback on the script and I've made some very slight changes. Not everyone gets how the leads dis-ease works in her life or how she overcomes that and being a single mom struggling. So yes, some minor changes in the dialogue with the surrogate sister will help there.
As for people not understanding the ending - none of the mothers who've read it were confused. This is a mother who will do whatever she has to so she can continue to be there for her daughter and so her daughter will not know that they are struggling as much as they are. It's one (very challenging) day in the life of this mom and daughter. And that is as much as I can say here, without giving it all away.