"She must pull herself together."
Translation:Вона мусить взяти себе в руки.
"I must do something" and "I have to do something" are, for all intents and purposes, interchangeable in American English (though "to have to" occurs more frequently in everyday speech). So, just to clarify, is that not the case for "мені треба робити це," "мені потрібно робити це," "я мушу робити це," and "я маю робити це?"
The first two are "need" and the second two are "must". You're totally right, "must" and "have to" are interchangeable. Just added this as a correct translation. Thanks!
Also, 'pull yourself together' and 'get ahold of yourself' are commonly treated as synonymous in American English. While I'm on the topic, 'a hold' and 'ahold' are both acceptable in this context, but 'ahold' may be more common in colloquial American English than elsewhere.