Naughton (20) and Ryan (27), who both have hockey backgrounds, are two of the three new players who have been identified as part of the IRFU's on-going talent identification programme.
The programme, which is open to the wider athletic and team sport community, offers elite athletes the opportunity to join an Olympic programme in what is a new and exciting international female sport.
Laura Lee Walsh - the other player selected via the talent ID pathway - made her debut as Ireland finished 12th at last weekend's Atlanta Sevens.
The competing squads have had to adapt to the Brazilian heat this week after coming from cold conditions in Atlanta.
There is an extra buzz of excitement around the tournament as of course, Brazil is the host nation for the 2016 Olympics when Rugby Sevens makes its debut at the Games.
IRB Head of Competition and Performance Mark Egan says the São Paulo competition will help to grow rugby in the South American country.
"The IRB is committed to the development of rugby in Brazil with nearly 8,000 boys and girls having been introduced to the sport via a variety of development initiatives in the last five years," he explained.
"So far, more than 500 teachers, coaches and referees have been trained in Brazil to sustain the growth and the IRB invested more than US$400,000 in both development support and high performance initiatives in 2013 to grow participation while increasing the competitiveness of the men's and women's senior national teams."
You can watch live coverage of Ireland's matches in São Paulo on wsws.irb.com, beginning today with their pool opener against New Zealand at 5.30pm Irish time.
For more follow @irbwomens on Twitter for updates from the weekend, using the hashtag #Brazil7s.
IRB WOMEN'S SEVENS WORLD SERIES - THIRD LEG:
BRAZIL SEVENS - POOL A FIXTURES:
Friday, February 21 -
IRELAND v New Zealand, Arena Barueri, 2.30pm local time/5.30pm Irish time
IRELAND v England, Arena Barueri, 5.36pm local time/8.36pm Irish time
IRELAND v USA, Arena Barueri, 7.58pm local time/10.58pm Irish time
Saturday, February 22 -
Cup, Bowl and Plate competitions (2.30pm-9.34pm local time/5.30pm-12.34am Irish time)
IRELAND WOMEN'S SEVENS Squad (Brazil Sevens, Arena Barueri, Barueri, São Paulo, February 21-22):
1. Shannon Houston (Blackrock/Leinster) (capt)
2. Christine Arthurs (Tralee/Connacht)
3. Niamh Ni Dhroma (Buccaneers/Connacht)
4. Nicole Cronin (Shannon/Munster)
5. Claire Keohane (UL Bohemians/Munster)
6. Megan Williams (Saracens/Exiles)
7. Aoife Doyle (Shannon/Munster)
8. Aisling Naughton (Talent ID Programme)
9. Nikki Caughey (Belfast Harlequins/Ulster)
10. Elaine Ryan (Talent ID Programme)
11. Laura Lee Walsh (Talent ID Programme)
12. Susan Vaughan (Railway Union/Leinster)