I am assuming that you are asking about the legal punishment that is enforced by the state, as otherwise there is no prescribed way to educate or discipline children. I think parents might try to adequately convey the seriousness of your action, but they will not any give any harsh punishment.
The Hadd punishment for theft is cutting the hand:
والسارق والسارقة فاقطعوا أيديهما جزاء بما كسبا نكالا من الله والله عزيز حكيم
[As for] the thief, the male and the female, amputate their hands in recompense for what they committed as a deterrent [punishment] from Allah. And Allah is Exalted in Might and Wise.
— Quran 5:38
However this has some precondition and does not apply in all cases of supposed theft.
Among the cases where it does not apply is when there is doubt regarding whether or not the thief had permission to enter the place of safe keeping and to take what they stole, and Hudood are averted because of doubts, this is the case for a person stealing from their parents:
ومن سرق من أبويه أو ولده أو ذي رحم محرم منه لم يقطع - فالأول وهو الولاد للبسوطة في المال وفي الدخول في الحرز
If a person steals from his parents or children or relatives in the prohibited
degree, his hand is not to be cut. In the first case, which is relationship
by birth, there is free sharing of wealth and entry into the hirz.
— الهداية في شرح بداية المبتدي [ English translation ]
ولا يقطع بسرقة مال الولد وإن سفل؛ لأن له تأويل الملك، أو شبهة الملك، لقوله عليه الصلاة والسلام: «أنت ومالك لأبيك».
وكذا لا يقطع بسرقة مال الأصل كالأب والجد وإن علا
The hand is not cut for stealing from the property of one's offspring, because interpretation can be made for ownership or there is doubt of ownership, and the saying of the Prophet ﷺ is: "You and your wealth belong to your father."
And similarly the hand is not cut for stealing from the property of one's ancestors, such as the father or grandfather
— الفقه الإسلامي وأدلته
سرقة الفرع من الأصل: ذهب جمهور الفقهاء (الحنفية والشافعية والحنابلة) إلى أنه لا قطع في سرقة الولد من مال أبيه وإن علا،
لوجوب نفقة الولد في مال والده؛ ولأنه يرث ماله، وله حق دخول بيته، وهذه كلها شبهات تدرأ عنه الحد
Stealing by an offspring from their parents: The madhab of the majority of the jurists (Hanafi, Shafi, Hanbali) is that the hand is not cut for stealing from the property of one's father etc. because the child has the right of obligatory maintenance from the wealth of the parent, and they are heirs in it, and they have the right to enter their houses, and all of these are doubts that avert the Hadd
— الموسوعة الفقهية