Is an eighty-year-old aunt sinful when she skips some verses of the Qur’an in her prayer recitation, and how can she be helped with that?

Reciting Surat Al-Fatihah is one of the pillars of prayer. If someone is unable to recite it correctly due to an ailment or forgetfulness, they must recite as much as they can, and what they cannot manage is waived for them, according to the Almighty’s saying: "Allah does not burden a soul beyond its capacity" (Quran 2:286), and the Prophet's (peace be upon him) saying: "When I command you to do something, do as much of it as you can." Prayer is not invalidated unless the worshipper omits something from Al-Fatihah or alters the grammatical vocalization in a way that changes the meaning, provided they are able to do so. As for someone who is unable, they should recite as much as they can. As for other recitations in prayer besides Al-Fatihah, omitting them does not invalidate the prayer.