Counters to Sivir Bot Lane
 

I'm thinking AD Malzahar so far. Any other ideas? My team might get mad if I take Jax bot when my teammates are thinking I'll go top.

Have you tried Nasus bot against Sivir?

No, I have not tried Nasus. How would Nasus counter Sivir exactly? Is it Wither? If so, then a good Sivir will Spell Shield, but then she can't Spell Shield Siphoning Strike.

except nasus gets wither twice as much as her shield
is super tanky has good sustain and can push just as hard

also maokai

An aggressive enough Yorik counters her pretty well. Also, a good Cass.

Yorick? Caitlyn? Cassiopeia?

I'd think Cass would do fine, sure Sivir can spell shield but Cass can just spam some more.

Spell shield has a mid cooldown, and sivir is squishy almost all gamelong, anything that can spam her and nuke her hard will win the line.

Cassio, Yorick, Ahri, even cait can win agains her.

Soraka out-sustains then outpushes Sivir, unless Sivir goes glass cannon. And if Sivir does that, just have your team gank her all day. Frozen heart is core anyway on Soraka, and combined with the armor buff heal makes Soraka pretty tanky. Sivir's shield isn't fast enough for the silence & if you block a q there will just be another coming in a second or so.

Nasus- Stand in the minions and dodge her Q. Use the minions to heal yourself and farm your Q. If she gets close enough wither, push the lane with your AOE.

Because pushing the lane is so easy with Nasus I usually put an in-range-Sivir higher priority target than the lane... since she can't do as much when you're chasing her off anyway, but you can with your aoe.

same way you counter morde, and ryze.

Idiots at top lane need to learn that sivir is incredibly easy to gank