It's been almost ten years since this happened to me. I was young back then, just a little fledgling; gullible and easily deceived. My older sister took advantage of that, and one night, in my mother's room, she told us a story. I didn't know why, but I was able to remember every word she uttered. It was about 8 in the evening then, when she told us that late at night, when we don't go to sleep, you'll see the curtains flowing and fluttering about. From there, an old lady will speak. "Let me in, let me in." I was so freaked out; I immediately tried to go to sleep.
Early morning I woke up abruptly. I knew from then that it was still too early, much too early. I was known to be the earliest riser of our family and before I was kind of proud of that, but that night, I regretted it. I lay awake on the mattress on the floor. Back then, when my father was working abroad, my mother made us all sleep in her room. When I woke up, I found out that I was facing my older sister and what a relief that was because a few moments later, I heard knocking on the window.
I found myself frozen from fear. I clenched my fists slowly and tried to regulate my breathing, the knocking was getting louder and louder. Then... It stopped... I almost sighed in relief when a voice spoke. "Neng, papasukin mo ako. Neng, neng, papasukin mo ako." (Kid, let me in. Kid, kid, let me in.) As she said this, she knocked continuously while I stared wide-eyed at my older sister's face. The knocking didn't stop and her voice kept on asking me to let her in. I wanted to cry but I knew that it'll only urge her on.
I didn't know for how long I laid there, frozen stiff from the fear, but when I heard the first clucking of the chickens outside, she stopped. I knew from then, that finally, it was morning, and I could only breathe shakily, as I tried to steel my frazzled nerves. I wanted to cry then, but I found myself unable to do so, because the only things ringing in my head were her voice, and the endless knocking throughout the early morning. What's creepier was that her voice was of an old woman, and that the window was behind me. She knew I was awake, even though I was facing away from the window.
Since that night, I never slept on that same mattress and demanded I sleep at another room and never in my mother's room again. What bothers me until now is why any of my other siblings didn't or my mother woke up when she made those noises? Why was I the only one awake? And why did she know I was awake when I didn't move an inch from the bed? Ten years have passed and until now I bring the memory of that first and last night she haunted me.
You may ask your sister too. If there's really such old woman knocking and pleading to let her in, then your sister kight really experienced it beforehand.