Is a blood pressure reading of 142/67 OK for 75yr old female

For a 1 time test it's hard to say. However, if you just sat down and took it, it's OK. Was this done by a med professional, home unit or in a store. Lots of people would love to have a BP like that, particularly at your age. I an a 76 YO male. Your numbers are very similar to mine, particularly if not a resting BP.

The 142 is a little high but not too bad for your age, and it depends when you took it, and how many times over days. It also depends on other health factors.
That 67 looks low to me in combination with 142, but I'm not a doctor!

You should be asking your doctor, nurse, or anyone in a clinic. Even a pharmacist, especially if you are on any medications.

Here's what the CDC says

Blood Pressure Levels Normal
systolic: less than 120 diastolic: less than 80

At risk (prehypertension)
systolic: 120–139 diastolic: 80–89

High
systolic: 140 or higher diastolic: 90 or higher