Thomas is the third on Kyle Smith's Scottish rink for the World Junior Championships, which begin on Thursday in Russia and act as the test event for next year's Winter Olympics.
Muirhead junior performed the same role at last year's World Junior Championships in Sweden that saw Scotland return to the podium with bronze after a year's absence.
Eve won the women's world junior title in 2009, which like this year's edition, was held in an Olympic host city in Vancouver and acted as the test event.
And while Muirhead senior, who is preparing for the senior World Championships herself, will seek insights from her younger brother on the venue she insists she won't be going overboard.
"I haven't been there [to Sochi] and I don't think any of us will go there and reccy it," said Muirhead, who was the skip of British rink that finished seventh at Vancouver 2010.
"I will definitely talk to him [Thomas] about Sochi and get as much information as I can, get a bit of inside knowledge, anything that can help really.
"But I don't want to overdo it because you don't do that for other championships like the worlds or Europeans although I did go to the world juniors ahead of Vancouver.
"The world juniors will have the same ice men and same umpires but the conditions do change and it will be different come the Olympics."