Can you put her in a coop next to the Blue Laced? If you hatch her eggs and she's producing, say, 30% of your eggs there's a chance 50% of hers will be Buff Laced, so 15% of all eggs likely to be Buff, plus 17.5% of those from the other three, who are producing the remaining 70%. That ups the possible % from 25% to 32.5%, so not that huge a jump?