Any risk in creating encrypted ext4 partition to shared drive?

I have a dual-boot Win7Pro-ubuntu 17.10 machine (8-core AMD-64 home built) with an extra 600+ GB hard drive that has a an NTFS partition for Windows backups occupying the second half of the drive. The first half once held an old ubuntu installation but is now unallocated space. I would like to put an encrypted ext4 data partition (visible only from ubuntu, of course) in that space. If I do this in the obvious way using the Gnome disk tool, is there any precaution I need to take to avoid damaging the NTFS partition?