Renee Fleming Williamson appeals her 210-month sentence for conspiracy to possess with intent to distribute 50 grams or more of methamphetamine. She challenges the district court’s denial of a three-level downward adjustment for acceptance of responsibility under U.S.S.G. § 3E1.1. We affirm “a sentencing court’s decision not to award a reduction under U.S.S.G. § 3E1.1 unless it is without foundation.” United States v. Solis, 299 F.3d 420, 458 (5th Cir. 2002) (internal quotation marks and citation omitted). Because Williamson failed to raise the issue before or during sentencing, plain error review applies. See United States v. Flores-Ochoa, 139 F.3d 1022, 1023 (5th Cir. 1998).

The district court did not err in relying upon the timing of Williamson’s plea in making the determination under § 3E1.1. See § 3E1.1 & cmt. (n.l(h) & n.6) (2008); United States v. Diaz, 39 F.3d 568, 572 (5th Cir. 1994). Nor was it error to find her guilty plea untimely for purposes of § 3K1.1 when she pleaded guilty on the morning of trial after denying responsibility for four months following her arrest. See Diaz, 39 F.3d at 572; see also United States v. Wilder, 15 F.3d 1292, 1299 (5th Cir. 1994) (holding that district court’s denial of acceptance of responsibility in reliance, in part, on the timing of the defendant’s plea on the eve of trial not erroneous). We also find no plain error in denying the adjustment despite the early weakness of the Government’s case, as the weakness resulted from Williamson’s concealment of key evidence. See § 3E1.1, cmt. (n.1(E)); Puckett v. United States, 556 U.S. 129, 129 S.Ct. 1423, 1429, 173 L.Ed.2d 266 (2009).

The judgment of the district court is AFFIRMED.