Comparing one's husband to one's brother

Q: If a woman says to her husband "did you take your phone with you to the shower?" And the husband says "no why would I" then the wife says "my brother takes it" and the husband says "I'm not crazy like your brother". After the wife says my brother takes it she gets a little scared as she read online that comparing your husband eith your brother affects the nikah. She now is doubting if she was calling her husband brother or had any such intentions as she got scared and felt she had. She wasn't comparing she was just saying how a trait may have been similar. Has the nikah been affected? Does comparing your spouse to your brother affect the nikah.

Receiving a gift when being paid back a loan

Q: I loaned a certain person an amount of R10 000 to be repaid after one year. When one year elapsed, the person repaid my loan and also presented a small gift to me (a box of chocolates) as a token of appreciation. I was neither expecting this gift, nor was it stipulated, at the time of the loan, that he would give me this gift. Is it permissible for me to accept it, or will it be regarded as interest?

Indexation

Q: Is indexation considered as riba? There are 2 methods to go to university

1. Paying upfront

2. Student loan (i know this is haram already but i just want to know about the 1st option whether it is actually halal because only a minority of Islamic scholars talk about this issue of inflation causing the prices to rise).

Zakaat on savings

Q: My question is related to zakat. If a divorced women with one dependant child is not working, and has a saving for her daughter's university education, does zakat apply on that amount of savings? Is this woman, who has no support, liable to pay zakat?