Makeup brush gift help needed

[NewOrleans]

My MIL had her makeup done at MAC months ago for a wedding. She liked the brush they used but didn’t buy it because she felt it was too expensive. I thought it would be a great Xmas gift but don’t know what they used on her. She said it was 38$ but they only have $35 & 42$ brushes. She showed me what she bought instead from Target— it was a medium fluffy face brush. She uses that Studio Fix powder foundation. Any recs for a MAC or Sigma brush to use with that product?

[hoteldweller]

Maybe a 135 or 127?