2nd hand Cannondale Prophet, or Prophet SL would be an ace choice. They’re the same frame, just the SL has a 190×50 shock instead of a 200×57, but you’re talking 67.5 head angle in the more upright position and about 66 degrees in the slack setting.
Trek Fuel EX frame is 68 degrees.
How slack does she want though? To me, going slack for slack’s sake, on a short travel bike, is counter productive. I think bike geometry generally has a sweet spot angle wise when it comes to the travel the bike has. I’d be looking at something that’s naturally around 69 degrees and designed to be 120mm both ends myself, with that in mind, may I present an absolute bargain of a complete bike…
http://www.paulscycles.co.uk/products.php?plid=m1b65s1p3709&tbv=CANNONDALE_RZ_ONE_TWENTY_3_Mountain_Bikes_Full_Suspension
She could sell off her current forks and any other kit, or upgrade the bike with them, but either way a full bike for £1k with spot on geometry and a brilliant frame… Not to be sniffed at I reckon.