The eight-year-old has already completed a half-marathon walk in honour of best pal Evie Harnes, who battles a severe form of juvenile arthritis. Now, she’s keen to up the ante and walk a full 26-mile marathon next year.
Evie’s condition can often leave her too tired to play, and Lexie was desperate to help.
The Williamston Primary School pupil decided to step up to the mark and raise money for the Scottish Network for Arthritis in Children (SNAC).
The keen swimmer, from Livingston, has already raised £2500 and is through to the final ten of the Mountain Warehouse charity challenge – hoping to add another £5000 to the total.
Mum Claire, 41, described Lexie as an “unstoppable machine” who saw no reason not to up the ante.
She said: “They must have been talking about charity at school and she said she wanted to do something for Evie.
“The two of them would do zumba together and Evie’s a great wee dancer. She’s a super wee kid, she’s so funny and wise beyond her years.
“But Lexie knows that sometimes Evie is limited with what she can and can’t do – sometimes she’s great but other days she’s sore and really tired.
“They still play together a lot, it’s just that Evie suffers for it the next day.”
About 12,000 children in the UK under the age of 16 have a form of arthritis – traditionally associated with older people.
But Evie’s is a rare form – known as systemic-onset juvenile rheumatoid arthritis – which causes high, spiking fevers, a rash, and joint aches all over the body.
Evie’s mum Sandra Harnes, 30, from Blackburn, was left terrified when her seven-year-old daughter was first struck down aged just three.
“She had been poorly for a wee while, it had been viral, then she deteriorated really quickly,” Sandra said.
“She literally woke up one morning and couldn’t move her body, she had a rash and couldn’t look at lights. We thought it was meningitis and had to get the ambulance.
“The type she has flares and subsides so by the time we saw the consultant it had subsided a bit and took a few weeks until she deteriorated again that she was diagnosed.”
Evie is now on medication to control the painful bouts. her family have been grateful for the help they have had from SNAC, which provides round-the-clock support.
Zumba instructor Sandra, who met Claire at one of her classes, said that the charity would be very grateful for “tough wee cookie” Lexie’s efforts.
“Evie is really proud of her. She’s got quite a old head on her shoulders and has been through a lot in four years.”
Tracy Rendall, chairwoman for SNAC, said: “Lexie is a true inspiration – we are all amazed by her sheer determination and selflessness. Walking a half marathon is a huge undertaking for an adult – for Lexie it was a mammoth task.”
Vote for the girls at www.mountainwarehouse.com.