Sakura can play defensive? 
Well, I guess c.HP can keep people out…
I don’t wind up playing a lot of Sakuras, simply because there’s not a lot out there, but I guess I can offer some insight based on my own personal tendencies, which may or may not mesh up well with other Dans.
Against Sakura, I’m not in a big rush to get inside and stay inside. She’s not a great zoning character, so I can backdash away from her at my leisure to taunt or set up a new approach. Some characters, like Ryu/Sagat/Gouken, Dan wants to get in on and stay in on because it’s a pain to approach them, but against characters without zoning tools (like Sakura, M. Bison or Zangief) Dan can dart in and out of range easily with his dash to confuse the opponent and keep them off-guard.
Once I am inside and putting on pressure, the Knee of Justice (Er, LK Danku, Sakura players might not know the terminology) will beat or evade almost anything she does on wakeup when done close. Using this, Dan can start up a frame trap pressure game of repeated normals into Knees to chip away, and eventually hit Sakura when she fails to block. A well-timed and well-spaced throw can disrupt this, or an EX Shouken (or however it’s spelled), but if the Shouken is baited out you’re looking at a nasty punishment combo. Dan will use this sequence to force you back into the corner, where things get really dangerous. Try not to get cornered.
There’s lots of generic sheDanigans as well, but those work on everyone for the most part. Blocked Dankus into throw/Koryuken/backdash mixup. MK Danku after knocking you down to cross up into a throw/Koryuken/backdash mixup. I don’t know if the standing LK Danku can cross up and hit Sakura like it can hit Akuma/Vega and others, but if it can, it’s something to be aware of even if there’s really very little you can do to stop it. As a poke, I’m pretty sure Dan’s s.MK outranges all of Sakura’s normals, so keep an eye out for it. It doesn’t combo into anything, so it’s not hugely dangerous, just something to watch if for some reason a footsie game breaks out.
There’s not really a lot else I can offer, unfortunately. Most of Sakura’s high-level game that I’ve seen is based around EX Tatsu combos leading to resets and lots of stun damage. That’s something where you simply have to play smart and watch the meters, and avoid being hit at the wrong times. It’s similar to the Dan matchup against Honda in that respect, where Dan can go all-out when Honda has no meter because then he has nothing that beats the Knee, but when he gets meter Dan has to play it a bit more safe and bait out the EX moves so he can go on the offensive again. I guess that leads me to one last note of caution. When the Knee of Justice is used well, there’s a lot of meter denial at work. Dan will build his EX meters very quickly with the Knee chains, while the opponent’s meter gain is very limited unless they can break out and muster some offense. Sakura really depends on her meter, so you have to be careful to avoid/escape the Knee lockdown, or else a lot of your options are going to be denied.
