It is correct that "i" translates as she/it. So in some contexts "i" would be she and in other contexts "i" would be it.
I think in Scotland, some people refer to the weather (it) as "i" and others refer to weather (it) as "e". I think that is related to the words for weather (aimsir and sìde) being feminine nouns.
On Duolingo, if I were doing a quiz on the weather topic, I might expect "i" to mean "it" (the weather). But I guess that won't always be clear on a quiz question. If you see it again, you could click the box to ask that your answer be included in the options for correct answers ("my answer should be correct").
Might interest some people, I’ve just found it – this i referring to weather is explained by Roibeard Ó Maolalaigh in his Scottish Gaelic in Twelve Weeks as coming from a reference to feminine oidhche night instead, rather than to the weather words (thus I guess a while ago people would say tha e brèagha during a day and perhaps tha i brèagha during night time, later i becoming more popular in some dialects, as taught in Duolingo) – this would be in line with Irish still generally using masculine sé when referring to weather.
Scottish Gaelic in Twelve Weeks, §5.43 The Weather, p. 62:
43 The Weather
The weather sìde (f) or aimsir (f) is an important part of daily conversation in Gaelic. Most conversations begin with comments on the weather. Here are some useful examples:
- Is e latha brèagha a tha ann. It is a lovely day.
Alternatively, we can simply use the verb tha as follows:
- Tha e brèagha an-diugh. It is fine today.
The feminine pronoun i rather than e is used in some dialects to refer to the weather in the above phrases; the feminine reference refers to, or originally referred to, oidhche ‘night’ which is a feminine noun.