Applying for apprenticeships

[WestCoastGirl]

Not sure if this is the right place to post but I just wanted some advice/thoughts for dd17 who is currently applying for admin apprenticeships.
She has 3 interviews lined up but would prefer the second job she is going for. The first two interviews are two days apart.
I'm not saying that she will be offered both jobs, or any at all but she is stressing about things already.
If she is offered the first job, should she accept it? Then if she is offered the second one, can she just tell the first one she has changed her mind?
I would normally advise this but the kind of jobs she is applying for all will be doing CRB checks and if she accepts the first one they may have already have started the process and I would feel bad that they have wasted time and money on this. I do over think things!
It may all come to nothing in the end but what would you advise?

It happens frequently where I work, people often accept jobs and later on, after CRB checks and references are obtained, change their minds. Employers are used to this I would think so don't worry about "upsetting" them.
Don't turn down a job on the off chance that a better one will be offered or she may end up with nothing.

Where I work our apprentice has to pay for their own dbs so it's worth checking who pays for it

Thank you. Yes insancerre I didn't think of that.