We all get frustrated. My son showed frustration when he was less than a year old and he was learning how to go down stairs (crawling). And it's a feeling that we continue to feel throughout life. It's an old and familiar feeling. And, yes, it is going to happen to both parent and student while learning to play an instrument.
Primarily, it's important to recognize the feeling.
Secondarily, create a plan. The plan:
1) make sure that you have all the necessary information (know what's expected and the specifics of what to do)
2) follow your instructions without trying to cut corners (sometimes by cutting corners we create our own frustration)
3) do your best... it may take you two days, it may take you two weeks. It doesn't matter, just keep working and doing your best.
Thirdly, Encourage, encourage, encourage. It's not that we "can't do it", it's that it's taking longer to do than we would like or were expecting. Sometimes we can get distracted with the final goal and not recognize that we've actually achieved many smaller goals, and indeed we're right on track to achieving the bigger goal.