For me it looks like you are just 1 or maybe 2 days late for watering. You just watered them so look again in 24 hours, if the leafs are back in form I'm just right 😅
Second guest is that she is just getting old and it's just the cycle of life, but I would guess it's my first option.
If you are using soil or coco I would advise you to use a "humidity meter for the soil" (sry I don't know the English word, that's why I put an exemple like from Amazon at the bottom). That's one of the easiest and safest way to water them on soil 👍
Thee added link is German Amazon and is just an exempel😅
Wendowerk Boden Feuchtigkeitsmesser für Pflanzen - [Grün/Schwarz] - Ohne Batterien - Verbessertes Feuchtigkeitsmessgerät Pflanzen [2024] – Premium Bodentester https://amzn.eu/d/gOUsCxa