I read that Lakshmi is the avatar of Durga in this article:
Gauri is seen as a milder form of Kali, which is why she wears a saree and ties her hair with a string of flowers. Sometimes, she comes as a single woman, and sometimes in a pair: the Jyestha Gauri (elder Gauri) and Kanishtha Gauri (younger Gauri), who are identified sometimes as Ganesha’s mothers or Ganesha’s sisters, or just friends. They are occasionally identified as Mahalakshmi++, who is not so much Vishnu’s wife but rather a local form of Durga, who is Shiva’s wife.
Also, in some movies and other articles (such as Wikipedia), they say that Durga incarnates as all the other goddesses, even Saraswati and Lakshmi, who are the Tridevi. They claim that Durga is more powerful than all of them and that only she is Adi Shakti.
Aren't the Tridevi suppose to be equal in power? Aren't all of them Adi Shakti? Also, if we follow these claims of only Durga being the ultimate, how can her avatars marry Brahma and Vishnu when Durga herself is already married to Shiva?
++ In this question, please do not assume that Mahalakshmi is a more powerful form of Lakshmi and whatnot.