I would expand it to in a relationship, be it a dating, a marriage whatever you have.

So, to me, it could use some of these options (and other as well):

Ela simplesmente chegou, me pediu um tempo e se foi (e vazou, saiu fora, etc e  tal...)

But she just walked in and said she wanted some time to herself and she was gone.

Article Source: http://EzineArticles.com/3549581

I just need some space.

I need some time off. (mainly if she/he is an athlete!)

I want some time apart.

(so it´s the same as one "asking a break", some time apart to think about things...)

Take care the break not turning into a (unintended) "break up", sometimes this happens when one want time to "confirm" their feelings and the other party thinks the former walked out on him/her!

On the other hand, it may signal that you are being too clingy on your partner/spouse

boyfriend/girlfriend, one needs a little space now and then.

The other side of that is: "when taking a break in a relationship, you have to be mature enough to realize that your partner may not want you back after it. Take responsibility." (I saw that in a site)

Well, my two pence.   Now it´s up to you, I hope it helps.