Hello Bobbi,
Your sister in law is fortunate in having you on her side.
You say that she has had to take early retirement, so I am assuming that she is below 65.
PIP is not means tested, so her pension will not affect her eligibility for it.
How to Claim PIP It is not always the easiest thing to successfully apply so do read our guides which are oozing with tips
PIP resources Yes, she is quite possibly entitled to esa and or uc have a look at this page, it is the guide I turn to.
New Style ESA / UC? The advice we give here is generic, she might wish to see someone locally who can give her personal guidance.
This can be a helpful link in locating someone. I hope some or all of those links help,
Catherine
