Overstaying in UK, appealing the leave to remain in the UK.

[Googol]

Hello.
So I am 18 year old, I completed my a levels. My parents overstayed the family visa, one of my parent became a British citizen in that time. Our request was denied when we first ask for the leave to remain but we got to appeal so now we are in the procedure of that. If we dont win the appeal what can we do? Since my parent is dependent on the other, will moving be, right. Also I have older siblings no older than 24 years old. And its been 10 years in this country. They want to remove us as family unit and we don't have any one in the homeland of my parents to look after us. What can we do if the appeal fails? Can we apply for a visa to Ireland? Should the British parent became Irish so we can move together to Ireland on dependent visa.