Hello. So I guess your questions is:
1. Which foundation to apply and should you take engineering/accounting/architecture as your mother suggests or your interest which is maths?
2. Should you follow your mother's recommendation (IIUM) or any foundation in public universities?

If my assumed questions are wrong, sorry.

For my answer:
1. First of all, for foundation, I think you will be specified into courses in public unversities such as in UiTM (Engineering, Science, Law, TESL), in UM (sains fizikal, sains hayat AFAIK), IIUM, UKM and other universities which have foundation.I cannot have a say for your future and it is up to you and your loved ones to decide.

You are at the age of deciding your future, what is interesting to you, deciding if you can take the courses that your mother recommends. Because from my experiences, there are some students that followed their mothers' recommendation but forced to quit halfway because of the pressure and cannot catch up with the studies,

and there are some that followed their mothers' recommendations but strives in universities. It is up to you and your determination in the end.
By the way, this is only my thought about teenagers that struggles with choices. As for me, I followed my thought during UPU season which is engineering, now I'm doing pretty well in my studies.

For engineering courses, I think I can describe a little bit as I am an engineering student myself.

For engineering, engineering maths are harder than add maths and maths at school, so if you think maths and add maths is something you can deal with it, with enough efforts, you can deal with engineering maths as well. For engineering, you have to score the science subjects as well (Physics, Chemistry)(Bio if you want to take biomedical engineering) because what you learned in high school will be used in engineering.

2. If you deal with Arab language, you can consider IIUM. AFAIK, my friends from IIUM foundation said that Arab language is compulsory. For on-campus accommodation, I think UTM also have on-campus accommodation (correct me if i'm wrong), but for other universities, you can choose options to make sure you can stay in college, from getting involved in college's activites, become athlete for the university, making sure the college's warden knows you and many more. But for me, your future maybe be brighter if you join these activites to sharpen your soft skills instead of staying years in college without doing nothing.

That is all from me then.
P.S. - once again, this is only my thought, if anyone have other way of thinking, feel free to continue your way of thinking. I'm open to it.

Agreed to this.