Depends on what you mean by safe. If you have anal sex without a condom and without lubricant, it's a) painful, b) one of the highest risks for STD transmission for both of you, and c) still possible to get her pregnant due to drippage from the anus into the vagina. So unprotected anal sex is not safe for anyone by any means.
However, if you're using condoms and lube, if you're starting out by using a finger to penetrate in order to see if your partner is enjoying it, and stopping whenever it hurts, then it's possible to be safe, but not without risk.
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