Sleeping at night query

I just wanted to post and ask if anyone has had their babies fall asleep for long stretches at 12 weeks or not. Over the past few days my LO has been sleeping between 8.5 to 9.5 hours straight before waking up on their own to be changed and fed. Then once they're back down to sleep, they will sleep for a few hours, wake up, go to sleep after being seen to again and then finally waking up at about 7 to 8:30 to start the day. Their bedtime routine at the moment is we will go upstairs to our room for about 6:45 and she will feed from me for about 35 to 45 minutes between each breast. I think during this time she's mostly seeking comfort and finds the closeness is enough to help put her in a sleepy state. Once she comes off the boob and I've burped her. If she shows no interest in wanting to feed anymore, I will put her on my chest and allow her to settle and fall asleep with a nice cuddle. After a few minutes I gently place her into the moses basket, cover her in a cellular blanket and tuck her in with her arms on top of the blanket. Sometimes she is still awake slightly (drowsy) but she's been able to gradually drop to sleep on her own where she doesn't cry out or cry herself to sleep. I immediately tend to her if she does cry longer than a few minutes and I either feed her if she's hungry or soothe her to sleep. I'm not a big believer in the cry themselves to sleep method. As we speak I am wide awake in bed, looking over at her just to make sure she's okay and so far she hasn't woken up yet and it's been over 9.5 hours. She is ebf and on Friday I took her to be weighed at my local library. In just her nappy she weighs 14lbs 9oz (6.8kg) which according to her chart means she's at a good weight. During the day she manages to nap a total of at least 2 to 3 times which last for about 1 to 1.5 hours each despite her protest in wanting one and I'm guessing this could be a contributing factor because she might be more tired. When she's awake, she's very alert and chatty and we spend time playing and interacting with each other, going out for car rides and walks about town and she's been eating well. I will either feed her every 2.5 hours or whenever she's hungry and these can last between 7 to 25 minutes. But I thought I should post on here and make sure there's nothing wrong or if there is anything I should be doing. I've been told by my friends that I'm very lucky she is sleeping this long without waking up. But being someone who worries. I want to just check if this is anything to be concerned about or if I should just enjoy it for now.