Are you still running SS?
I just re-read some of the programming since I am running an LP for a second time, and you can certainly get more than 3-5 weeks out of it. The key is to know how to prevent and overcome stalling. I missed this the first time, but when it starts getting hard, drop your incremental increases - start adding five pounds to your Squat and Deads, 2.5 to your presses.
Then, if you miss reps, just repeat the weight the following workout. If you miss reps in consecutive workouts, drop the weight by 20% and start over.
Then, you can add a light day. For example, you squat 200 on Monday for three sets of five, squat 140 for 3x5 on Wednesday, and go to 205 for 3x5 on Friday. Take two days off and squat 210 3x5 on Monday, 145 on Wednesday, 215 on Friday.
Finally, you can go to 3x3 to continue the LP before switching to intermediate programming.
For 5 pound increments, you can buy fractional plates. I just bought 2 plates of 1.25 pounds on amazon for about $20.
Just offering info that I read. You’re doing fine, keep it up.
FWIW, my daughter just turned 14 and she’s 5’6", about 160, lol. She is also tall for her age.