Changing size of display in iframe

Hello,

I have set up a site for my family history (portersof heckington.com) and using an iframe I’ve imported a website from Rootsmagic. This appears on the Family Tree and Individual Profile tab, but the index of names for some of the surnames is too large for the window available, so when you scroll down not all are available. I’d like to know how to make the frame containing the names larger, so they can all be viewed.

Thanks

Nigel

https://wordpress.org/plugins/iframe/