The 31-year-old Samina reached the top of the 8,611-metre peak early on Friday as part of a seven-member local team, and was followed hours later by a second Pakistani woman, Dubai-based Naila Kiani.
A Nepali Sherpa broke her own record reaching the 8,849-meter (29,032-foot) summit for the 10th time - the most times any woman has climbed Mount Everest.
Sirbaz, 32, hails from the Aliabad area of Hunza in Gilgit-Baltistan and began his climbing career in 2016. Sirbaz is aiming to become the first Pakistani to climb all 14 of the world`s highest peaks.
She was accompanied by climber Shehroze Kashif — who has attained the title of being the youngest Pakistani mountaineer to ascend the peak — and Nepalese sherpas.
The feat was a "personal challenge" to show that women can "do extraordinary things," Tijerina said in messages to AFP hours before going down the volcano, which is also known as Citlaltepetl.
Scaling up to 8,849 metres, she reached the summit at 8:02am on Sunday, along with Pasang Temba Sherpa. She has also become the first non-Nepalese climber to reach Everest's summit this mountaineering season.
His father Kashif Suliman also confirmed that Shehroze has successfully scaled K2 on Tuesday morning and made history. He said Shehroze began his journey towards the ‘Killer Mountain’ two weeks earlier.
A senior official told AFP that Canadian Richard Cartier and Australian Matthew Eakin were missing on K2, while Briton Gordon Henderson was lost climbing Broad Peak. "We cannot declare them dead until the bodies are found."
The two — Shehroze Kashif, who last year scaled K2 at age 19, and Fazal Ali — went missing on Tuesday after scaling Nanga Parbat, known as “Killer Mountain” because of its dangerous conditions.