Is it wrong to use general template design from your peer?
If it's a corporate template created by the Marketing department (or marketing person, or your boss) then it's normally published somewhere that's available for all employees to use. A colleague might even create a template for your team, and deliberately publish it somewhere for everyone to use. Using these templates is normally fair game, and is often preferred because it gives a consistent brand identity across all presentations by the team / company, especially when presenting to external customers.
However, from your description it sounds like your colleague spent time and effort creating a unique design for her own use that she felt helped her deliver presentations to her internal colleagues with more impact, and you simply co-opted it into your own presentations without even asking for permission.
That's pretty inconsiderate because now her presentations look like yours and in the worst case without any attribution people might even think she copied your presentation.
You might argue that in a workplace, everything created by staff is owned by the company, but colleagues still have feelings, so normal social rules still apply - if you take something that's not yours without permission people are going to get upset with you.
The best thing you can do is try to heal your working relationship by apologising for not asking first, and tell her it won't happen again. Hopefully she'll see that you're the sort of person who tries to put things right when you make a mistake and will give you another chance...