Limit Internet Bandwidth for Devices: Manage COMTREND VI-3225u Router & Improve Ping in Games

Hello.
I wanted to ask for help.
Well, I like to play a game in the evening. I do not have any problem with this if there is no brother and sister at home then it's okey.
But the problem starts when the "exploiter" ... namely the sister starts to browse YouTube then the ping jumps to 120-240 ms
I wanted to ask if there is a way to set up a router / web page (Router control panel) to set up a smaller internet for the internet ... or the entire Wi-Fi
So, for example, I have 40-50 ms and she has slower movie loads
I have cable internet with Orange 10mb \ s
Router: COMTREND-VI-3225u-5F0F
I am asking for help because it is uncomfortable ... and she would not even notice when the film loaded her for 1 min longer

Read the Comtrend manual
http://www.orange.pl/ocp-http/PL/Binary2/1985578/4066465551.pdf
Check,
I do not see QoS on this equipment.

exchange a router for Mikrotik + some ADSL modem working in bridge mode, take some time to learn RouterOS and do what you want: split bandwidth, set priorities or even turn off your sister YT as she will be pulling too much

Unfortunately, the change of the router is gone for several reasons
Kraniec_Internetów reviewed the instructions and it turned out that the default address 10.0.01 where you configure Router is given a bad model ... I came to this because I read the instructions that you gave me and there I had other options.
Proper Router Comtrend Vi-3225u Multi-DSL IAD
I read page 45-46 in this manual what you gave but I still do not know what to change there, you could lead me please the hand like a small child I would be grateful to Ps. It does not have to be given a high priority, it might as well be reduced the speed of the entire Wi-Fi because it only uses ... and brother in the evening, but it's not enough And blocking Yt on her Ip is the last resort
Instructions: https://www.orange.pl/ocp-http/PL/Binary2/1999945/4095887878.pdf

OKAY,
then, as in this router you will not be able to set it to turn off WiFi in it, and as an AP, use something that gives such an opportunity, eg Mirotika

And it will slow Wi fi down?

And the basic speed also at 2
?

Added after 2 [minutes]:

and something else to change it because I can only select: /

I'm afraid I can not edit this just to check

You can also set it up, just have a bit of desire and simply log into the router ...