Is it permissible for a husband to sell his wife`s jewelry if he was in a hard up?
                                A woman`s jewelry and dowry are her own property, and it is forbidden for the husband to take either without obtaining her approval. However, it is desirable for the wife to support her husband through considering her jewelry a sort of documented debt on him.
                             
                        
                            
                                
                                Is it permissible to repeat the Istikhara (seeking guidance) prayer, and is it a condition that one should sleep after offering it?
                                All perfect praise be to Allah,The Lord of The Worlds                                                                                                                                                            Istikhara is offered once, but it is permissible to repeat it, and sleeping after offering it is not a condition for its validity. And Allah Knows Best.
                             
                        
                            
                                
                                What should a sick person, who is incapable of fasting, and who didn`t make up for missed fasting days, do?
                                One who has missed fasting days is obliged to make up for them, but if he/she wasn`t able to because of an incurable disease , or old age, then he/she has to pay a ransom which is feeding a needy person for each of the missed fasting days. And Allah Knows Best.
                             
                        
                            
                                
                                Is the son of the sister by breastfeeding considered a mahram in Islam, and is it permissible for a woman to go for Hajj with him?
                                Everything that is prohibited by lineage is also prohibited by breastfeeding. The son of the sister by breastfeeding is considered a mahram, just like the son of the sister by blood, and it is permissible for him to be her mahram for Hajj and Umrah. And Allah Knows Best.