I need to leave one out...wich one

So is that 6 days? I would make sure to go to Sevilla and Granada. If its 6 days, I think you just have time for the two great Andalusia cities. (Cordoba is amazing, too, but not on your list)

I’ll just say that you are correct when saying you don’t have time for all of them. I’d keep the same ones Jules suggested.

So you have from the 5th to your daughter's departure on the 13? So really 8 days (not counting her departure day), and you have to end up in Barcelona, correct? I'd either do Sevilla/Granada/Barcelona or Valencia/Barcelona. Don't try to cram everything in.

yes the 4th we leave Madrid around 4 pm.... and she leaves from Barcelona the 13th in the morning, from there we go to Nice

So, what are a must?? Seville or Valencia?? Cordoba or Granada?? ... how is the minimal in that place? like where I need more time, and where I can visit the must seen in 2 days or 1 day 1/2 ??

Of Sevilla, Malaga, Granada, Valencia, I would say the "musts" in terms of history are Sevilla and Granada. Cordoba would be the third great Andalusian city. If you want to look at it geographically, Granada, Valencia to Barcelona makes sense. It really depends on your interests and how much time you want to devote to getting from place to place.

We did 2 nights in Granada. We could have easily done 3, but 2 was fine, and one wouldn't have been enough. At least 3 nights in Sevilla would be optimal if you go there. I haven't been to Valencia yet so I can't speak to that, but Barcelona really should be at least 3 nights. I'm not a huge fan of Barcelona-- I much prefer Madrid and the other cities you're considering. But wherever you choose, it's best to give yourself time to see the area instead of rushing through to fit in more sights.

If it were me/us, we would do day trips from Madrid while your daughter is studying — to Segovia, Toledo (have not been), Avila; then head to Seville for three nights; to Cordoba for one; to Granada for two nights; then end in Barcelona. While the Alhambra is amazing, we enjoyed Cordoba and the awesome Mezquita much more. Segovia is lovely and walking the walls in Avila is fun. Barcelona is worth a couple of days primarily for Sagrada Familia and, perhaps, Recinte de Sant Pau. Malaga is deserving of a stop but you likely will not have the time. Happy planning.

Seville
Granada
Cordoba if there’s time but I don’t think you have enough nights. Count nights not “days”. Don’t waste a lot of time traveling. Three or four hours in Seville is much more memorable than 3-4 hours on a train.

While Malaga and Valencia are very nice to visit, for me they just do not rate as high as your other options. By Spanish standards they are secondary destinations (yes, Cordoba is also more important).

While the map may suggest Granada-Valencia-Barcelona would be a good route, in fact there are not direct trains running between Granada and Valencia; you have to spend 8 hours on a bus or travel by train through Madrid (which I don't think is much faster).

I make the above suggestions despite the expected oppressively hot July weather in Andalucia, because I know that topic was covered in your earlier thread and you're prepared to melt.