Questions & Answers about Она увидела объект.
Because this is the past tense feminine singular form of the verb увидеть (to see, perfective).
In Russian, past-tense verbs agree with the subject in gender and number:
- он увидел = he saw
- она увидела = she saw
- оно увидело = it saw
- они увидели = they saw
So since the subject is она (she), the verb must be увидела.
This is a question about aspect, which is very important in Russian.
- увидела comes from увидеть → perfective
- видела comes from видеть → imperfective
In this sentence, увидела suggests a completed event: she saw / caught sight of the object.
By contrast, она видела объект could mean something more like:
- she was seeing the object
- she saw the object (without emphasizing completion)
- she had seen the object / was familiar with seeing it, depending on context
So увидела объект is the more natural choice when talking about a single finished moment of noticing or seeing something.