Use the boomerang when she is above or below you, because either it'll hit her, or she'll be forced to block it with her fair, and putting her on the defensive by blocking the boomerang allows you to hit her before she is able to pull off another move, and if she moves away, no loss, seeing as you want her away from you. Bombs are your friend, as they stuff her enough for you to up air or dair her, which is the best way to kill her.
Up b out of shield is effective if you see the Jiggs mis-space an aerial or if she attempts to land right behind you for an up tilt (or if she tries any ground based moves that are laggy, like f smash or dash attack, in which case, depending on which way you are facing, you could grab instead). If a Jiggs lands behind you, NEVER jump out of shield, they will up tilt rest you. Roll away from her, and there isn't really anything she can do to you because she is so slow.
Almost always tech away from Jiggs. She is not fast enough to catch you, and if you tech in place or towards you can be punished. This does not apply when you are too close to an edge and teching away moves you nowhere, so your best bet is to not tech, and just do your standing animation.
This whole match is basically about projectile setups, spacing, and priority. Arrows aren't that useful due to the lack of hit stun and damage, not to mention the arc they fly and the leg. Y.Links are actually useable, but not Link. Boomerang and bomb to aerial, space fairs, out prioritize with nair.
To recover, if the Jiggs comes out after you, up b into her. If she tries to place herself between you and the level below the edge, sweet spot the hookshot. She shouldn't be able to come from behind you, because if she remains and the stage, sweetspot a hook shot.