I really liked Peggy. With any cozy mystery, you have to expect a little off-the-wall behavior from the main character and I think this was done just right. She wasn't a dimwitted idiot like a majority of the protagonists; while her actions were occasionally reckless, she was never stupid. The fact that she was highly educated and a scientist made me like her more.
Also, older ladies getting into new romances is great to see in media (even if it is just in print). It's not something that happens very often.