Of course you can do it easily !
First of all, you need to create new partitions for eOS Distro (including his own swap if you have one for Mint (if both use the same swap, it's could have effect if you hibernate one and you boot the other one).
When you install eOS, or every linux distribution, by default an installation of grub is part of the linux distro installation. And grub can detect you windows, your mint and your eOS.
If you don't want to risk anything, do not install grub when you install eOS. After that, boot on your mint distribution. Then update your grub list using
sudo update-grub and the new eOS will appear.
The best way to install multiple distro without risking anything between them is to use UEFI Bios and GPT partitions. If you do that, you can boot directly from the UEFI bios into your prefered partition which contains OS. But for that, you need to setup your bios as an UEFI bios and all your installation must be in GPT mode (and not MBR). If your current installation is not UEFI, this is a lot of work and risks. But for my PC, I have this installation and I can boot from UEFI bios even I destroy an OS boot, an SSD or whatever.
Boot faster because your boot a partition, not the GRUB Loader. (I boot directly into windows, I press F8 while my BIOS is booting to get more choices (Hackintosh/Windows 10 for me), I press F2 to setup default configuration into my UEFI bios directly.
No dependency between your loader (because there is no loader like GRUB) and your multiple OS installation. Your OS depends directly from your UEFI Bios.
You can add and remove partitions easily with no risks (don't delete the wrong partition, that's all).
If you have more question, you can ask me (my english is poor, sorry for that).