Kitty-Cat Problems

So, we're having this problem with our little kitty-cat.  She is 2 1/2 years old, and has NEVER had a litter box problem before.  But recently, she is going (just pee-pee) in places other than where she is supposed to.

About a month ago, she pee-pee'd on the dog's bed.  Twice.  I thought that maybe the dog antagonized her and she got back at her for being a pain.  Like, "there... you wanna come after me?  I'll pee on your bed!"
So, I had to throw the bed out because it was soaked right through and you can't wash the inner part... just the cover.

Two days ago, she did it again on the NEW BED I JUST GOT! (I wasn't too happy.)  Once again, the bed was in the trash.

Last night, I got up at 4:00am to take the dog out, and when I came downstairs I was like, "hmmm... smells like pee-pee down here!".  So I went right over to the dog's now pseudo-bed (a couple of old blankets layed on the floor.. she HATES it!), but the bed was dry.  Thank goodness!  So I figured it was just my nose being overly sensitive now.

This morning, when my 10 year-old was getting ready to leave for the bus, he slung is bag over his shoulder and wrinkled his nose and said, "eww... something smells."  I thought he meant dog poopie because the dog had just gone out, but she didn't poop.  So I was like, "well, the guys have been laying mulch, and that tends to smell a little."  He goes to school, and I think nothing of it.

He came home just a little bit ago, walks in the door, and says, "mom, remember I said something smelled this morning?  Well, smell my backpack.... the cat pee'd on it!"  I was like, "WHAT???"  Sure enough, I sniffed and there it was.
I went over to the side door where everyone comes in and takes their shoes off, lays their bags down, etc.... and to what does my wandering nose appear???? 

SHE PEE-PEE'D ALL OVER MY TOTE BAG AND THE SHOES THAT WERE THERE!!!!

As you can see, I am very upset over this.  This is very new behavior for her and I'm not quite sure what to make of it!

Does anyone out there have cats and have ever had a problem with this???  I've had cats before, and they NEVER did this!  She is an indoor cat, and this is the first indoor cat I've ever had.. could that have something to do with it???

If anyone can help me please, please, please comment!

I made an appointment to go to the vet on SAt. morning because my neighbor suggested that maybe she has a bladder infection or something????

Ugh, this is really upsetting me because I don't want my husband (who was VERY opposed to a feline) to say "that's it... out she goes!"

I'll be waiting patiently for any input!  Come on all my feline loving friends... let's hear what you've got!