Cate
Long term member
I'm glad your sister has decided to join you in becoming healthier.
With intermittent fasting, the 16/8 method, which is probably the easiest & most popular, involves fasting every day for 14–16 hours and restricting your daily eating window to 8 hours. She could choose to have that eating window between any hours, depending on what suits her, but eating first thing in the morning & then again in the evening doesn't fit. 10 am -6 pm or 11-7, 12-8 etc would fit the 16/8 method.
With intermittent fasting, the 16/8 method, which is probably the easiest & most popular, involves fasting every day for 14–16 hours and restricting your daily eating window to 8 hours. She could choose to have that eating window between any hours, depending on what suits her, but eating first thing in the morning & then again in the evening doesn't fit. 10 am -6 pm or 11-7, 12-8 etc would fit the 16/8 method.