OP, if you're going to do PNH, it's got to be all the way, no steps omitted, as others've said. It's Level 1 first, in the order of the steps given. Before you even think of haltering her, you spend a half hour hanging out in her area, as described by RockinD. It's all about the relationship, & this is step 1 of it. Then, you never hide the halter, that's sneaky. And so on, as mentioned.
Plus, if you're going with PNH, you'll want to get your Level 1 skills tested, to go on to Fun & Confidence in L2, & if you can't walk up to your loose horse, showing her the halter, without her being pinny & worse, turning tail to you, you flunk!
I hate to see you get confuddled by advice that won't cause you to develop the skills to at least graduate L2!
Tons of Good Luck to you & mare!