SEONAID McIntosh isn't just gunning for a medal at the Commonwealth Games, she is aiming to out shoot her big sister.

Youths discharging air rifles are usually met with disdain but the 18-year-old who leaves Dollar Academy for university this summer is no ordinary teenager. Having been born into Scotland's foremost shooting dynasty, how could she have been?

Mother Shirley has won four Commonwealth shooting medals for Scotland, more than anyone else in history, earning an MBE for her services for the sport. Her father Donald is another stalwart, having competed for Scotland at the Manchester Games in 2002 before becoming head rifle coach at London 2012 and Scotland's shooting team manager for 2014. Last but not least comes big sister Jen, who memorably followed the family route into folklore with two golds and a bronze in Delhi in 2010. Their total of seven medals, three of them gold, makes for a busy mantelpiece, although London 2012 ended unhappily for Jen, one of just two Scots in the shooting team, with a 42nd-place finish in the air rifle.

Seonaid has been shooting since the age of nine, helped, like her mother and sister before her, by the cadet force at Dollar Academy. She has only managed to overcome Jen, 23, on one occasion, a "fluke" in the prone event.

But there is something mischievous about the teenager's demeanour which suggests she quite fancies her chances some day, if not this summer, in the two events, small bore rifle and 10m air rifle, where the pair will be in direct competition at the Barry Buddon shooting centre in Carnoustie. There is a healthy disrespect between these sibling rivals, but nothing would please them more than sharing a podium like the Brownlee brothers, Alistair and Jonny, who took first and third in the London 2012 triathlon.

"I am more competitive with her than she is with me ... maybe because she is so much better than me," said the youngest member of the McIntosh clan. "In fact, until I was about 15 I wasn't going to do shooting at all, because it was Jen's thing.

"Then she went to Delhi and did really well. And I was like 'actually, I might give it a go'. We used to play tennis, just for something to do on a Saturday, and I was always trying to beat her at that as well. I am always trying to beat her at everything. But I tend to come second quite a lot. I reckon if I beat her at the Commonwealth Games it is probably going to be really difficult for a few days afterwards. But she [Jen] said to me the other day that she wanted us to be like the Brownlee brothers, that she didn't really care which colour the medal was, as long as it was first and second. If I shoot my best, a medal is definitely in my sights."

For all her formidable genetic inheritance and extraordinary talent, McIntosh is also just an ordinary teenager. A drummer in the pipe band at school, she rejects the notion that she was pushed into her sport, and still wonders what her school pals make of it all.

"A lot of them think it is really cool," she said. "And a lot of them don't know about it at the moment. I guess they are about to find out."

For all her lack of years, McIntosh's Games place was threatened by an arthritic condition in her knee which is more commonly associated with older people. Thankfully her arm and hands, the parts that really matter, are unaffected. "No-one in my family has it," she said. "But it doesn't really affect my hand or fingers, not at the moment, just my knee. I do sometimes get pain getting up and down to do the prone, but in the Games I am shooting air rifle so I am standing up. I don't let it bother me any more."

Being part of the McIntosh family may mean there is pressure to succeed, but there is also a formidable support network to help you do it. "There probably is a genetic expectation for me to perform well but I am just kind of ignoring it," she said. "The first time I held a gun I was at a Scottish shooting event and my dad was like 'here you are, give it a go'.

"My parents never pushed me into it. They were like 'if you want to do it, it is your choice'. My dad is not the coach, he is the team manager, but he has coached me in the past.

And my mum is obviously experienced as well. So if I have problems with something they can all just kind of put their views out there, and Jen is really helpful as well. I've never actually seen my mum's medals, I will have to do that when I get home."

While the pair hope to be in close proximity on the Glasgow 2014 podium, McIntosh junior would rather they aren't forced to live at close quarters at temporary flatmates during the Games.

"Hopefully not!" she joked. "I guess we get on each other's nerves - me more than her I guess. We didn't have to share a room growing up, at least not since I was one or something like that. But she is always there if I need her. No matter how much we fight, we still love each other."