Husband asking for the mahr back after divorce

Q: Can you please advise me on the following matter: 

A divorce took place approximately 13 years ago. The husband (and his family) are now requesting return of the gold coin which was given to the girl as her mehr when they performed the nikaah. However, in 2021 the house was burgled and the coin together with all other valuables were stolen. 

Questions: 

1. Is the girl now obliged to return the coin if it is in her possession? 

2. Considering that the gold coin has been stolen, is the girl under an obligation to recompense her ex-husband the value of the coin? 

3. If compensation is what she must do, then which value must this compensation be determined, i.e. at current value or the value 14 years ago?

Making a second jamaat in the masjid

Q: I have read a few times that men should not join the second and third jamaats in the Masjid. 

In the UK, many of the Masajid are very small, serving a large number or Muslims. However, in recent years they have introduced second and third jamaats to avoid people praying on the pavement which is used by everyone public. 

Is it still the case that instead of joining the second jamaat, men should pray alone in the Masjid?

One's supplier delivering directly to the customer without one taking possession

Q: I want to ask is drop shipping permissible or not? Let me explain the workflow. 

When a customer places an order, I contact the supplier to say that a customer has placed a specific order. The supplier then charges me the cost of that product from my bank account and then delivers it to the customer. So in that way, is it permissible or not?