It's honestly not fun for most characters against Sheik, Puff included.
That being said, Puff definitely has plenty of tools against her. Puff's neutral game absolutely destroys Sheik, cross-up Nairs to land behind her shield, and spaced Bairs can quickly rack on damage and eventually hit her offstage for an edge guard opportunity.
A smart Sheik will play the Puff matchup very campy and try to use needles, or needle --> Grab to get you in the air. In many cases you won't get rest opportunities on a patient player, but it's definitely good to learn the setups:
- As stated above, CC --> Rest (Or rest out of shield) Dash attack
- Rest ducked grab attempts
- If you catch sheik with an Upair at around 20-40ish percent it can lead to an ariel rest.
- Downthrow (at relatively low percent) to tech chase rest.
- And many more (PM for questions)
For edge guarding you should either force sheik onstage to punish with rest/ariel attack
OR
You can meet sheik early offstage with a Fair (due to it's lengthy hitbox duration) and either hit them before they Up-B, catch a jump, or to bait it out and hog ledge.
The matchup requires a lot of patience and is by no means easy for puff. It counters newer Sheik's incredibly hard, but your free rests start to disappear as you play against better smashers. If you'd like to know any more, just send me a PM with questions.