The facility has already helped groom 100 national and one world champion as well as Commonwealth Games medallists.
Ms Jones, 18, from Bangor, Gwynedd, recently brought back a gold medal from the Youth Commonwealth Games in Apia, Samoa.
The grant-funded extension has new physiotherapy and activity areas.

The GMB union said women care workers, cleaners and janitors had been subject to pay discrimination in comparison with their male counterparts.
The union said improved offers had now been made which put members in line for "significant equal pay awards".
The council described the offer as a "positive step" in ending the dispute.
North Lanarkshire Council Leader Jim Logue said: "I have made it clear since becoming council leader that we will settle equal pay claims where these are justified.
"I am pleased to say this agreement in principle, which is subject to further discussion, with the GMB union, is a positive step towards that aim.
"This is a major milestone which I hope will mark a departure from the confrontations of the past. We have negotiated in a sensible and constructive manner with the GMB and its legal advisers to reach agreement."
Councillor Logue said the council had paid about Â£100m in equal pay claims in recent years and wanted to resolve the issue.
GMB Scotland organiser Hazel Nolan said fresh negotiations began after "a recent change in leadership at the council".
"Improved settlement offers subsequently followed, meaning GMB Scotland members can now look forward to significant equal pay awards," she said.
"The new council leadership immediately recognised the need to resolve this inequality and their willingness to work with GMB Scotland in negotiating a proper settlement means our members are at last getting justice.
"Our 'Equal Pay Now' campaign was organised after our members, including home care workers, cleaners and janitors, were forced into a protracted dispute with North Lanarkshire Council's previous leadership over pay discrimination in comparison with their male counterparts."

Sophie Tucker, 23, from Devon, admitted making up the allegation that he forced her into a sex act after the fiance saw his boss leaving her home.
Police later found intimate photos and messages she had sent to the man.
Tucker was ordered to attend a thinking skills course, by the judge at  Exeter Crown Court.
Judge Ian Lawrie called her "selfish and cowardly".
The court heard she had invited the 50-year old to her home.
The man spent almost seven hours in custody and had to submit to having samples taken by a nurse.
The court was told his business suffered.
Judge Lawrie told Tucker: "You must have known what you were doing was going to make life very difficult for [the victim].
"You showed selfishness and cowardice which are deeply unappealing."
She said: "I am thoroughly sorry about what I did and if I could do something to help him I would.
"It was a stupid thing to do. He has not done nothing. I wish I could undo it."
Gold medal weightlifter Catrin Jones has opened a £125,000 extension at the Holyhead and Anglesey weightlifting and fitness centre.
[NEXT_CONCEPT]
An agreement in principle has been reached to end a long-running equal pay dispute between North Lanarkshire Council and about 200 female staff.
[NEXT_CONCEPT]
A woman who falsely accused her fiance's boss of a sex attack was given an 18-month suspended sentence for perverting the course of justice.