Gale was the intended victim

I always wondered what her intention was. Seems a bit risky to kill Gale in the van in broad daylight. When did she plan on killing her?

Thought that, too. In fact, since we know Mrs. Loomis is the one who kills Randy, it strengthens my theory that she was only out to kill Sidney and Gale herself (for killing Billy... Gale for shooting him and Sidney for finishing the job, which would have been well-publicized) while leaving everyone else to Mickey, and that she only attacked Randy because he picked up the phone instead of Gale and got too close to the van when he started badmouthing Billy. The fact that she's hiding in Gale's van and calling her cell phone points strongly towards her being the originally intended victim.