Is there any evidence or mention of who Frieza's mother is in any of the new Dragon Ball Super, Dragon Ball Z , Dragon Ball GT, or any of the manga?
As a trivia: in the totally non-canon Dragon Ball AF (fan-made) manga drawn by Dragon Ball Super mangaka Toyotarou, Frieza's mother was the West Supreme Kai...– Brian HellekinJan 27, 2019 at 3:41
We have never seen a female member of Frieza's race, let alone Frieza's mother.
As for mentions of her in the anime, note that Frieza's mother is only referenced in the English dub of Dragon Ball Z, not in the original (where only a "father" is mentioned). It could very well be that this race was intended to be unisex, which is a possibility raised here. In the video game Budokai Tenkaichi 3, there are brief mentions of a "mother".
The wikia article on Frieza's mother concurs:
Frieza mentions his "parents"/"loving parents" to Goku on Namek in the manga, anime, and Dragon Ball Z: Battle of Z, whereas he simply mentions "his father" to Goku in Budokai Tenkaichi 3 and Dragon Ball Z Kai. It should be mentioned that the plural form does not exist in Japanese and thus Frieza's mother is only mentioned in the English dub.
In Chi-Chi's commentary on First Form Frieza and Final Form Cooler in Budokai Tenkaichi 3, she mentions parents instead of just King Cold alone, stating that Frieza and Cooler's upbringing by their parents is a troublesome story. Chi-Chi also refers to Frieza's mother in King Cold's profile, wondering if Frieza's mother has the same face as Cold.