Treating children equally in practice

I apologize if this sounds silly but I see a lot of advice on this and similar subs about treating all children equally in a blended family, but can someone please describe what this looks like? I am a SM and my DH and I have a BD 6 months who lives with us 100% of the time, SKs10&12 EOW. With the age gap and the difference in time they’re spent here, it’s difficult to see what getting treated equally looks like. Obviously we don’t give them the same things, or offer the same activities. We also have little influence over the SKs lives. Also, I do things for my BD that my husband hasn’t done for his older kids, like open a savings account and put $ in, and travel to visit my mom.

Is treating equally spending time with them when they’re here? Using the same level of kindness? But even then, you treat a 6 month old so different than pre teens.

So ultimately, Any insight or further explanation is helpful! Again I acknowledge this should be simple but am struggling with the practice of it.