The "FRIDA KAHLO CORPORATION" (FKC) incorporated by Kahlo's estate in 2008 and seems/claims to be owner of all IP rights concerning the artist, including trademarks. This company manages and licenses these trademarks which contain Frida Kahlo's name and image.
In this regard, it is said that the trademark rights were previously assigned from Kahlo's descendents (namely her niece) to FKC.
Recently, an artist produced dolls which represented Frida Kahlo for sale on an e-commerce website, namely Etsy. Upon realizing the same, FKC filed a complaint and as a result the products were removed from the Etsy website. However the artist counter-attacked through filing a suit with the US District Court in Colorado, claiming "interference with prospective business advantage" and "deceptive and unfair trade practices", and also claiming that her use was not in fact infringing.
Here it is to be noted that image rights to Kahlo have expired, considering Kahlo has died over 65 years ago, however there are current and valid trademark registrations for the same.
The current debate is to differentiate to which extent enforcement of trademark rights can be enforced when it concerns historical figures, in other words where will the lien be drawn between the use of historical figures and infringement of trademark / copyright / image rights.
Currently there are a few other conflicts concerning the Frida Kahlo trademarks ongoing. Firstly, the Kahlo Family successful requested injunction against Mattel (a famous toy manufacturer) in 2018 after they sold dolls which representing Frida Kahlo and her image. Moreover, FKC also faces conflict concerning their Intellectual Property with the company VersaLicensing, as they allege that this company has been falsely representing trademark rights of Kahlo's name and image.