Translation:She goes to the supermarket for the ninth time.
Dredward, she goes to the supermarket nine times = Ela vai ao supermercado nove vezes.
Just because when you say "nine times" you are just counting, speciyfing the quantity of times she has gone to the supermarket. However, the context here is different. It's something more like "It's the ninth time she goes to the supermarket".
This is true when we are dealing with SINGULAR NOUNS. With plural nouns just add an S: pelas/pelos
Adjectives follow the Gender of the Nouns in Portuguese. The noun VEZ is feminine (uma vez) , so the adjective nono (masculine) becomes nonA (feminine).
the translation is "she is going", I wrote "she will go"....wouldn't "she is going" be "ele está indo"? we wouldn't say ela vai ir, so I assumed ela vai is will go...
"She will go" would be "Ela irá". "Vai" may be used as present or as future. Mostly of the time is implicit what is the time, but when is not indicative of time is probably present.
It's a real challenge translating into present tense in English, since you'd hardly ever say it. I started imagining it was on a list of things that happened a few days ago, but in real life you'd almost always say "She's going to the grocery store for the ninth time." (They must say the word "supermarket" somewhere, but not much here in Canada.)