The seven-year-old has risen 30lb in the weights since registering a first success over obstacles at Folkestone last November, securing three victories at Newton Abbot since the start of May.
Paddy Brennan takes over in the saddle for the first time this weekend, but Henderson is hoping for some rain to aid his mare’s cause.
“She’s gone up 12lb and it’s a step up in class for her,” said Henderson.
“The first time she won for me she won off 99 and she’s now up to 129.
“I think the rain will help her and she’s fit and well.
“Paddy has never ridden for me before, so I’m looking forward to it.”
Peter Bowen saddles Rio Gael and Heron Bay.
The former has been plying his trade of fences of late and returns to smaller obstacles for the first time since placing fourth in Haydock’s Swinton Hurdle in May.
“Rio Gael would have to have a chance on his Swinton Hurdle run. If he can reproduce that form he should run very well,” said Bowen.
“We’re just putting a visor on him as he can be a bit reluctant to start, but once he is off he’s fine.
“Heron Bay ran a nice enough race the last day, where he just needed the run a bit.
“He should come on a fair bit from that, so hopefully he’ll run well too.”
Steve Gollings would love to run Laterly, a hugely impressive winner at Aintree on his latest start.
But the locally-based handler may be forced to reroute to the Galway Hurdle if the ground continues to dry out.
“I walked the track on Wednesday and I’m just worried the ground is going to be too fast,” said Gollings.
“This has been the plan for a while and we also gave him an entry in the Galway Hurdle.
“I would love to see some rain. There is up to 15 millimetres forecast but I don’t think it’s going to arrive until late Saturday afternoon, which will be too late.
“We’ll walk the track at 1pm and if we’re not happy with conditions, we’ll take him out and look at going to Ireland.
“If Overturn doesn’t run there, we’d get in with a lovely racing weight and I think he’d have a right chance.”
The Howard Johnson-trained Caravel is well handicapped on the pick of his form.
Johnson now hopes the application of cheekpieces and a tongue-tie will bring about a return to form.
“He likes to go right-handed so the track should suit,” said the Durham handler.