Donna Kelce is treasuring the early days of her son Travis Kelce’s engagement to Taylor Swift by holding on to keepsakes from the milestone moment.

“Donna is already saving little things from this time like photos, notes and flowers,” a source tells PEOPLE exclusively. “She is very sentimental about it. She wants to remember every detail, so she has been holding onto mementos from their first days as an engaged couple.”

Swift and Kelce, both 35, announced their engagement on Tuesday, Aug. 26., sharing a series of photos from a garden proposal at the Kansas City Chiefs star’s home in Missouri. The ring, which Travis designed with Kindred Lubeck of Artifex Fine Jewelry, features a vintage-inspired look.

According to the source, “Taylor and Travis have been in celebration mode ever since the engagement. They are not in the wedding planning phase yet. Right now they just want to enjoy being engaged and they are going to take their time with it.”

“It has been a relief not having to keep it a secret anymore and they are glad it is out in the open,” the source adds. “Both families are overjoyed. There were toasts, happy tears and everyone is thrilled for them.”

“Friends have been stopping by and sending little gifts. It has all been intimate, nothing over the top.”

The couple’s engagement comes after a whirlwind year together. Swift was first spotted cheering Kelce on at a Kansas City Chiefs game in September 2023, and the pair went public with their relationship soon after. Since then, they have supported each other through Swift’s record-breaking Eras Tour and Kelce’s successful NFL career.

Meanwhile, the proud mom swapped out her Facebook cover photo after the Super Bowl champion and the pop superstar announced their internet-breaking news.

The NFL mom, who also shares son Jason Kelce, 37 with their dad, Ed Kelce, changed the image to a throwback shot of the engaged couple as kids.

Both photos give off an elementary school picture day vibe, with Travis against a blue backdrop dressed in a red plaid shirt and sweetly smiling for the camera. Swift, meanwhile, was posed against a tree in a white collared shirt, a black jumper and held a leafy sprig in her hand.

The change in image on Donna’s Facebook profile was the mother-in-law-to-be’s first public gesture after Travis and Swift’s engagement. She has yet to publicly comment since the exciting news broke.

Last month, PEOPLE exclusively reported that Taylor and Travis have “talked about the future a lot.”

“They’re in a really solid place and more in sync than ever,” a source said at the time. “They’re both all in.”

On July 24, fans noticed a meaningful shift in the couple’s dynamic when the NFL athlete posted the Grammy winner on his Instagram for the very first time. The photo dump included 13 images of Travis posing with loved ones, and seven of them featured an appearance from Swift.

“Travis posting Taylor on his Instagram for the first time wasn’t random, it was intentional,” the source continued. “They’ve been private in their own way, but this was his way of showing how serious things have become.”

“There’s no pressure between them, but they’re very aligned on where things are going. He makes her feel safe and supported and she brings so much joy into his life. They’re really happy.”