Consent needed to add a member's phone number?

I am a ward clerk and a member's record was recently moved into our ward. There was no phone number associated with her record. We did some digging online and found her phone number. Am I allowed to add her phone number to her record without her consent?

Perhaps a better question is "is it accurate"? Some information found on the internet can be for a different person of the same name, or an old out of date number.

I think it would be better to make contact with them first.