William, it used to be that any WikiTree member could approve a new member and I'm sure that has not changed, but what has apparently changed is our ability to get to the new member's profile page where we can do it. That is because all living persons who are not already members are automatically assigned Unlisted privacy, which is a very recent change in order to comply with the EU's new requirements.
Please edit the tags in your question to more quickly bring this to the attention of those who can make whatever software changes are needed to permit you to approve her. You can remove the tech_help and unlisted_profiles tags because nobody follows those, and add sysops and bugs and greeters as three new tags.
The recent privacy changes have wide ranging effects on other functionality that need to be addressed. Thank you for bringing this one to the forefront.
EDITED TO ADD:
You can forget changing the tags as I recommended above! I just checked her profile and discovered that she has already volunteered. She also signed the honor code. Note that the Unlisted notice says that she is now a member (so you don't have to approve her) and that she needs to change the privacy on her profile because members are not permitted to have unlisted profiles.
Can you write to her and walk her through changing her privacy level? If not, we need to get a greeter to do it.