Jack and Jill bathroom in the middle should help you get more space for the 2nd room.
Some ideas below, just food for thought

Even children need closets, and those two bedrooms have no closets!
The kids can share one Jack-and-Jill bathroom centered along the top of the drawing, with a door from each bedroom or one door from the hallway.
There will also be doors from the hallway to each bedroom. When kids share a bathroom with two doors, they will lock the other door for privacy and often forget to unlock it. I solved the problem by using matching key-locks and hung a key on the doorframe just inside each bedroom. When one forgets to unlock the doors, the other will have a key and won’t have to enter the other’s room to unlock the bathroom door.

Here is a simple Jack and Jill with the bedroom doors coming in from the same wall. Skip the WICs and do back to back reach in closets behind the bathroom to the other wall.

I forgot to add that in this scenario you could only have the locking door on the water closet preventing the scenario of a locked door above.

Thank you very much. well i have thought about jack and jill bathroom but my older one is refusing to share a bathroom with the little ones and doesn't mind having a tiny bedroom. i don't know what to do.

That tiny bedroom will diminish resale value.

My thought is-it's your house, so you get to decide the arrangement. If you want the jack and jill bathroom w/the similar sized bedrooms, (which makes more sense) then that's what you should do. If the older one doesn't want to share, the older one can use a different bathroom and doesn't get their own. Because really, you know what's going to happen---once it's all said and done, the older one is going to start complaining b/c there's not enough room and "it's not fair".

Oh, the joy of children! Other than the jack and Jill I don't know what else could be done. Perhaps just separate vanity areas? Would that make the older one happy? It's not like the tub or toilet would be used by more than one person at a time.
At a bare minimum get the bathrooms on the same wall so the plumbing is together.

"Thank you very much. well i have thought about jack and jill bathroom but my older one is refusing to share a bathroom with the little ones and doesn't mind having a tiny bedroom. i don't know what to do"

It's amazing what children stop "refusing to do" when they have no other option. Build the house that you want and don't let anyone who isn't paying the bills think s/he gets to dictate the terms of it. I agree with Missi Rogge.