Answer by taking a quote from the following article:

Tamannaah Bhatia was born on 21 December 1989 in Mumbai, Maharashtra, India, to Santhosh and Rajani Bhatia. She has an elder brother, Anand. Her father is a diamond merchant. She is of Sindhi descent.

In 2005, at the age of 15, she played the female lead in Chand Sa Roshan Chehra which was a commercial failure at the box office. The same year, she made her debut in Telugu cinema with Sri and in Tamil cinema with Kedi in 2006. IndiaGlitz in its review called Tamannaah as the "real scene-stealer" and stated that she "walks away with all honors", adding that her characters have shades of the characters played by Vijayashanti in Mannan (1992) and Ramya Krishnan in Padayappa (1999).  Her first release of 2007 was Shakti Chidambaram's Viyabari in which she played the role of a journalist who wants to write an article about a successful entrepreneur played by S. J. Suryah. The film opened to negative reviews and flopped at the box office, but Tamannaah received praise for her performance. She got her breakthrough with Sekhar Kammula's Happy Days and Balaji Sakthivel's Kalloori, both of which featured Tamannaah as a college student. She won critical acclaim for her performances in both films. The commercial success of Happy Days and Kalloori established her career as an actress in both Telugu and Tamil films. Her performance in the latter earned her a nomination at the 56th Filmfare Awards South in the Best Tamil Actress category.  Her first release of 2008 was the Telugu film Kalidasu directed by debutante G. Ravicharan Reddy. She was paired with debutante Sushanth, the grandson of actor Akkineni Nageswara Rao. Upon release, the film opened to moderate reviews and critics felt that she looked good and very romantic but had less scope to perform. The film was an average grosser at the box office. She later made a cameo appearance in the Telugu film Ready followed by another cameo appearance in the Telugu - Tamil bilingual Ninna Nedu Repu titled Netru Indru Naalai in Tamil.

what happened in 2005?
In 2005, at the age of 15, she played the female lead in Chand Sa Roshan Chehra