Is it obligatory to repeat the ghusl if, after performing it, one remembers the presence of waterproof mascara that was not entirely removed before the ghusl? And is it obligatory to repeat the prayers of the two days that were performed after this ghusl?

Eyelashes are part of the face, which must be washed during wudu (ablution) and ghusl (ritual bath). If a woman applies mascara or other cosmetics to her eyelashes and it forms a barrier preventing water from reaching the skin, she must remove it for purification. Otherwise, her purification is invalid. If you do not know whether the water reached the skin underneath, the default assumption is that it did not. You are not required to repeat the entire ghusl; rather, only washing the eyelashes is sufficient because continuous washing (muwalat) is not a condition for the validity of ghusl according to most scholars. You must repeat the prayers you performed with that incomplete ghusl.