Short answer: it’s the Polo Ralph Lauren striped silk‑blend sundress (the exact “Striped/ Shirred Silk‑Blend” midi she wore). You can get that exact dress in/ship to Singapore — or buy very similar striped smocked midi dresses — from the places below.

Where to buy the exact Ralph Lauren dress

• Ralph Lauren boutiques in Singapore (try in‑store so you can try sizes): Takashimaya (Orchard), Paragon, VivoCity and Shaw Centre — call the store first to check stock. (ralphlauren.com.sg)
• Online retailers that ship to Singapore and currently list the Ralph Lauren striped silk‑blend/midi styles: Mytheresa (SG site) — shows the shirred striped silk‑blend midi — and other global shops like Net‑A‑Porter, Farfetch and The Outnet (all carry Polo Ralph Lauren and similar striped dresses). (mytheresa.com)

If the exact dress is sold out

• The dress sold out quickly after the engagement photos, so you may need to check multiple stockists or look at close alternatives. Retailers and shopping roundups list similar smocked/striped midi sundresses at ASOS, Lulus, Anthropologie, Free People and other retailers (good options if the Ralph Lauren piece is gone). (brides.com)

Quick practical tips

• Call the Ralph Lauren store nearest you to reserve/try the piece (store phone numbers are on the Ralph Lauren Singapore locator pages). (ralphlauren.com.sg)
• If you order from an international site, check shipping times and duties to Singapore (Mytheresa, Net‑A‑Porter, Farfetch and The Outnet show Singapore pricing/shipping options). (mytheresa.com)
• To copy Taylor’s styling: look for a black‑and‑white smocked/bodice + full A‑line midi with thin straps, and pair with tan block‑heel sandals. Fashion coverage identifying the dress: Marie Claire / Fashionista / ELLE. (marieclaire.com)

If you want, I can:

• Check current stock/links for that exact Ralph Lauren item at Mytheresa, Net‑A‑Porter or the Ralph Lauren Singapore stores right now and paste direct buy pages (I can do that for you).