Kitten meowing LOUDLY at night

Since I'm a new kitten Mom, I could use some advice.I have no idea how old Blaze is, though we estimate her to be around 6 months.....we found her as a tiny thing and therefor don't know her age.She's been inside our home since she was brought here.If she gets outside, we immediatly catch her and get her back inside as we don't want kittens.(We've had her for about 4 months)
Now on to my question,
over the last two nights, she has meowed so LOUD at night, that it wakes me from a dead sleep.I have 2 box fans going and due to a recent surgury have to take Ambien to sleep at night.I have 4 kids, so every slight sound I hear to make sure they are o.k. But, I didn't expect to wake to hearing her sound like she's in pain.
Can she be in heat? Is she sick?Lonely?
I close the kids doors at night..............she can't get in their rooms to keep them awake by licking their faces and etc.She can come into our bedroom.....but chooses to stay in the Living Room on HER couch
I called our Vet and made an appt. for her to be spayed Monday.Just wondering if that is all it is.Thanks!!!

One of the signs of a cat in heat is loud vocalization. Glad to know you're having her spayed.

The vet will check her over and make sure she is healthy to have surgery...and will tell you if there is anything else going on...but more likely than not she is in heat.
I`m glad you are getting her fixed...it`s better not only for her but maybe you`ll get some sleep yourself now too! :-)
Linda

It does sound like heat. But the vet will examine her before the spay so that they can verify that she is healthy enough for surgery.

Recently I moved to a new apartment and finally had the chance to bring my cat Sibohan to live with me. Unfortunately she and my parents Cat Duke love eachother, I thought they just tolerated one another. So for the past few days since I brought her to the apartment she has been waking in the middle of the night and yowling (yes she is fixed), I think she's trying to find him. So This weekend My parents are bringing me their cat Duke to live with me. It dosn't sound like your cat has had another kitty friend that it misses but I'm just saying Cat's are just like people and have to vocalize their lonliness.
Good luck with everything!