How do I save Ashley?

Solution 1:

There's actually a host of factors that influence the outcome of this interaction. What it comes down to is whether the Survivor trusts you. Whether you've built up enough trust with them will determine whether they will believe you outright when you confront them, require a hard, or possibly even max level Charm/Intimidation check to persuade (this appears to be what happened to you, but sadly, you don't have enough Paragon/Renegade points to make it through), or if you've been truly neglectful and/or hostile, they may be unable to be swayed.

These factors include:

• Whether you saved the Council in the original Mass Effect
• Whether you pursued a romance with them in the original Mass Effect
• Your response in conversations on Mars regarding your prior work with Cerberus, and whether you can be trusted.
• How many times you visited them in the hospital between missions, and your gift, if applicable.
• If you romanced them in ME1, whether you pursued a different romance in ME2
  • If you did, whether you were honest and/or apologetic about that alternative romance.
• Your use of Paragon or Renegade interrupts in the final conversation.
• If Major Kirrahe or Thane Krios survived the first two games and saved the Salarian Counselor. If the Salarian died, Udina will show doctored footage implicating you, which makes the whole interaction much more difficult.