I posted on your other thread but basically when a rabbits GI tract starts to slow down the ingested hair that would normally pass straight through begins to collect together. If the rabbit dehydrates it will clump into a hard dry mass, forming a blockage and making the use of gut stimulants dangerous.
The fact it is passing is good news but you must keep syringing her liquids, warm water is fine.
'Furballs' in rabbits are secondary to stasis rather than a cause.