The first few dozen Google results, when you type "molly" in quotations, is about the drug:
"3,4-methylenedioxy-methamphetamine (MDMA) is a synthetic drug that alters mood and perception. It is chemically similar to stimulants and hallucinogens. MDMA is commonly called Ecstasy or Molly."
Any developer may have a lot of work to do to get a website/service/product to rank higher than all those in the SERPs.
That unfortunate obstacle aside, beautiful name. Common-girl-name domains are popular for a wide variety of branding and project names. Especially female fashion and cosmetics and accessories and arts and... well, that's just the tip of the iceberg. Does not need to be related to female products at all. Tons of companies use female names as branding. Lynda.com (for learning), Ashley.com (for furniture), Mary.com (for games) come to mind immediately. Could make a long list if I were to think about it.
I agree with above valuations. There's a wide swing to the prices, as it depends entirely upon the scope of the potential buyers' projects, and their funding. But anywhere in the low, medium, or even high xxx,xxx range for this one.
Superb domain. Too many uses (and potential buyers) to name. Taken in 187 extensions, according to DotDB. And part of the domain string of thousands more. Even some of the multiple-word companies (eg: MollyMaid) may like this one, as a shortener for re-branding?
Good luck