The 36-year-old singer can`t believe Phoenix - her child with first husband Jimmy Gulzar - is now 13, though she still considers her eldest girl to be her "baby".
Mel - who also has four-year-old Angel with Eddie Murphy and six-month-old Madison with current spouse Stephen Belafonte - said: "Phoenix has just turned 13, I can`t believe I`ve a teenager on my hands, I feel old.
"She`s a little bit moody because she`s a teenager but we`re very close. She`s my first so I still consider her my baby, she`s a sweetheart."
Mel is so close to Phoenix, she even let her name her youngest sister, and insists she wasn`t worried her daughter would come up with a wacky moniker for the tot.
Speaking on UK TV show `Lorraine`, she said: "Phoenix was there at the hospital with me and I said, `Why don`t you name your sister?`
"I mean, everything about Phoenix is very funky and very stylish so I knew she`d pick a nice name."
Mel can next be seen hosting `Dancing with the Stars` in Australia - a contest she came second in the US in 2005 - and though she is nervous about her first presenting job, she is relieved not to be taking part in the celebrity dancing competition this time around.
She said: "I`m glad I`m hosting because those rehearsals are a killer. Your feet hurt because of the shoes ... it`s hard work.
"I`m going to be nervous hosting but I like a challenge."