Gifting An iPad

Hello,

I recently purchased an iPad as a gift for my grandmother. I would like to have it set up for her prior to giving it to her. She already has an iPhone and has an Apple ID (which I have the password to) I wanted to get it set up for her but if I sign into her Apple ID will it alert her phone? Meaning if I sign into her Apple ID and start putting things on the iPad. This is a surprise gift so I don’t want her to know ahead of time. Is there any way around this? This is the newest iPad 10.2inch 32GB