My dad has been separated from his wife for 10 years and he recently passed away. Does she collect his VA benefits and pensions?

The benefits she may be entitled to some. As said Aid and Attendence maybe one if she has health problems. Dad would have needed to serve during wartime. But if he has a pension from serving in the Military (like 20 years) I think the pension dies with him. This subject has been asked recently and a read that when Dad retired he would have needed to pay into a survivors pension for Mom to receive anything after he dies.

Best thing is to call the County VA office and ask them. The amount of years they were married would be important. Also, having his military discharge and other records.

The answer is almost certainly yes if they were not divorced.

If they were separated and not divorced, she is his widow and dependent. You will have to contact the VA on what she is entitled to.
Most of the time, the spouse does not get the pension, unless the couple had paid an extra bit back to the government to allow the survivor to get it.