What should I ask potential childminder?

[smallpotato]

There is a woman on our street who works at a preschool and also does after school childminding. I asked her this morning about possibly looking after my 3yo and 1yo for 1 day a week when I go back to work, but it was just a brief chat and she said she would look at her work schedule and get back to me. However I'm sure there are a million questions I forgot to ask her!

I've never used a childminder before- are they supposed to be 'registered'? If so, who with?

Do childminders usually accept childcare vouchers? If she doesn't do it at the moment can I reasonably ask her to set it up?

How much do they usually charge? Is there usually a discount for 2 kids?

Anything else??

I don't know where you are but if in England (Scotland and Wales have different rules) childminders have to be registered with Ofsted. If she is registered she will have her certificate and public liability insurance displayed at home (it's a requirement). Ask to see her latest inspection report. Prices vary depending on where you live so I can't give any advice on that. The same with discounts for sibling ... some offer discounts some don't. Also ask to speak to other parents .. I always volunteer this as I think it's good for a prospective parent to chat to somebody who is already using or used my services.
With regards to childcare vouchers ... if she is registered childminder I see no reason why she wouldn't want to use this method of payment. I use two voucher companies and never had any problems. It doesn't cost anything to sign up so if I had another parent who wanted to pay via different voucher scheme I would have no problem with signing up.