You meet Millie during the “Key to her Heart” and CJ has to date her afterward until their relationship reaches 35%.

Where can I date Millie?

The best places to go are to the Steakhouse near her house, or The Craw Bar or World of Cog near the Old Venturas Strip. Dancing: Likes to go to dance clubs. The closest one to her is east of The Camel's Toe, the casino in the southeastern section of Las Venturas.

How many dates do you have to go on with Millie?

After 3 successful dates, she will call you to let you know she has left the security card in her bedroom, asking for reassurances that she will share in the profits from the heist.