I think the easiest way would be to use a fixed font like Consolas as opposed to other scalable fonts. This is especially useful if you have a multi-line string with fields that need to line up together - like decimal points, right or left justified, etc. Scalable fonts will squeeze the text differently depending on the characters in the string.
The Draw.TextFixed() documentation explains how you can print using a specific font.
https://ninjatrader.com/support/helpGuides/nt8/draw_textfixed.htm
Hope this helps