There are following rules for alternative names in our Contribution Bible:

Name
The primary stage name someone uses.

Many actors (and non-actors) use multiple stage names in their career. When a name change is linear, you should use the last name used by a living person. e.g. Caitlyn Jenner, Alexa PenaVega rather than Alexa Vega.

When a person uses many names simultaneously and alternatively, choosing a primary name is usually a judgment call based on a few factors: Is there a name they are most often credited as? Which name is used on their official website and social accounts? Which name is used on their agent or union's website? Which name are the other major websites are using?

There is more (6) credits as Michelle Cuneo than Michelle DeLynn (5) on her IMDB profile, so I have left Michelle Cuneo as her main for now and added Michelle DeLynn as her alternative, so TMDB search for this name should work. These records are not locked though, so If you feel that her name should be changed (e.g. as per her official website if there is any), you can switch alternative/main on her profile.

HI, Her twitter is @MichelleDeLynn, her single name, maybe she has changed to Cuneo since her marriage to Paul Cuneo. Just in case it helps, I am not sure which name should be the first. Regards.

maybe she has changed to Cuneo since her marriage to Paul Cuneo

One more argument for Michelle Cuneo as her main name, but as I said, I have left that field unlocked, so it can be changed eventually. Anyway, thank you!