It wouldn't be completely bad if she was a signer if you require two signatures. If not, perhaps I might worry (a lot of things play into they whys and why nots)
We have our President (Me) and the treasurer as a signer. We cannot have the VP (my husband) because, well, he's my husband!
But we could technically put anyone we want on the account.
Rule of thumb, if you are insured, make sure it is someone who is covered under that insurance.
It is really up to you. What are the odds that she will have to sign a check anyway? The purpose of multiple signers is really only set up for emergencey situation.
In our group the 3 people with signing abilities are the treasurer, the VP, & the seceretary. Normally it is the Prez, but our prez declined and said she would rather not have signing power.
She and I (I am the VP) are always together anyway.
The treasurer will sign all of our checks anyway and in an emergency situation I will hold the checkbook. So unless something happens to me as well, our seceretary will never have to sign a check.