Reference check: okay to use my internship manager even though I wasn’t hired?

Hi everyone, I’m a recent accounting grad and I’m in the final stage for an entry-level accounting role. The company asked for 3 professional references and will email each person a short reference questionnaire.

One of my best potential references is my manager I worked with during my internship. I worked with them the most during the internship, but I didn’t get a return offer afterward, and I’m worried they may have had the most influence in that decision.

I emailed them to ask if they’d be comfortable being a positive reference (including if the form asks if they’d recommend me for a role) and they replied that they’d indeed give me a reference and gave me the email to use. Still, I’m anxious that she could answer negatively on the questionnaire.

Questions:

•	Is it generally a bad idea to use a manager as a reference if you didn’t get a return offer for an internship?

•	If she already agreed to be a positive reference, would you trust that and use her?

Or should I use someone else?

Thank you for any advice!!