Cause this is a present continuous sentence not a present indefinite/simple past. If you wanna ask something then ask me cause I'm an Indian and I know Hindi fluently. And my name is Kaustavmoni Wary. And don't ask why then I'm learning Hindi cause I've to up my XP cause I'm learning Spanish
There is a lot of confusion on this thread, so I'll try to sort it out.
First, as you've probably realized because you are asking about it, रहा, रही, & रहे are exactly like "-ing." They are added to verb stems to make a verb continuous. But they only go with verbs. खड़ी is not a verb, or a form of a verb, or related to any verb. It's an adjective. So it never goes रहा, रही, or रहे.
Hindi does not in fact have a verb for "to stand." It only has an adjective that could translate into English like "stand-y" as in "she is stand-y." That sounds silly to English speakers so we always translate it as "standing."
It's made worse by the fact that Hindi has verbs for things like sit down and lie down and worse still by the fact that the adjective meaning stand-y even looks like a verb form! But it does not conjugate. Because it's not a verb.
If you want to talk about standing and you really, really need it to be a verb, you can say खड़ा होना (होना = "to be") and you can perform all the conjugations on होना. Like वह खड़ी है. That's how it works for "to be happy," "to be ready," etc.
Hope that helps. Have fun and keep asking questions.
It's the verb ending which makes the meaning standing. The woman has already done the action of standing up (up being implied) so it's not a continuous aspect. It's a state of being in standing position. If the meaning were "this woman stands" then the action stands is in the process of happening. It's similar for sitting. Unless one is in the immediate act of sitting then this ending implies a state of being. Does a native speaker agree with me on this?